Retaining Wall Installation Manual for Commercial

Transcription

The information and product applications illustrated in this manual have been carefully compiled by
the Allan Block Corporation and, to the best of our knowledge, accurately represent Allan Block
product use. Final determination of the suitability of any information or material for the use
contemplated and its manner of use is the sole responsibility of the user. Structural design analysis shall
be performed by a qualified engineer.
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Commercial Installation Manual for
Allan Block Retaining Walls
®
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Printed on
Paper with 10%
Recycled Fiber
©2014, 2011, 2008 Allan Block Corporation, Bloomington, MN Phone 952-835-5309, Fax 952-835-0013, US Pat. #5,484,236, #6,792,731, #6,322,742 & #6,854,236 Canadian Pat.
#2,012,286 & #2,133,675 Australian Pat. #682,394 & #133,306 Europe Pat. #649,714 & #99,308,421.9 Germany Pat. #69,423,563.6 Japan Pat. #3,142,107
Mexico Pat. #189,846 Taiwan Pat. #NI-72269 AB Fieldstone Pat. #7,775,747 & D624,204S Int’l And Other Patents Pending DOC. #R0514-1214
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Looking Towards the Future
The next generation of Allan Block products is
here; AB Fieldstone - Green, Natural and Friendly.
The patented two-piece system enables us to
push the envelope in aesthetics, sustainability,
and product opportunity.
So look to the future with us as Allan Block
continues to innovate. Expect to see more of
AB Fieldstone and all it has to offer as the next
great wall solution, from the company you have
come to trust – Allan Block.
About Us
With the same plan, design and build process as the
other Allan Block retaining wall systems, you can
now have AB Fieldstone. The most innovative Green,
Natural and Friendly product on the market.
Allan Block is a leading provider of
patented retaining wall systems for
large-scale commercial, industrial,
roadway and residential projects.
AB Fieldstone Typical Reinforced Wall Cross Section
For over twenty years, Allan Block
has been helping landscape and
construction professionals build better
walls. With hundreds of millions of
square feet of Allan Block in the
ground, we can deliver the quality
and performance you need. Our wide
range of products allows you to be
creative, efficient, and confident on
every job.
Thank you for using Allan Block.
1
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Table of Contents
Allan Block System
Allan Block Products
Built-in Engineering
Gravity Walls
Reinforced Walls
Other Reinforcement Options
Plan/Design
Develop a Plan
Design Evaluation
Build with AB and AB Europa
Gravity Wall Construction
Reinforced Wall Construction
No-Fines Concrete Backfill & Installation
Working with Soils
Compaction
Water Management
Build Patterned Walls with AB and AB Europa
Wall Patterns
Patterned Wall Construction
Patterned Wall Construction Tips
Build with AB Fieldstone
AB Fieldstone Construction Tips
Construction Details with AB and AB Europa
Finishing Walls
Curves
Curves with Geogrid
Corners
Corners with Geogrid
Stairs
Terraces
Design Details
Construction and Inspection Checklist
Material Estimate Worksheet
Geogrid and No-Fines Estimating Charts
Specifications
References
Charts and Tables
Products
Standard Product Specifications
Maximum Wall Heights
Soils
Setback
Friction Angle and Soil Weight
Minimum Radius
Geogrid and No-Fines Concrete
8
9
11
13
15
17
18
19
22
24
25
26
30
32
33
34
36
37
38
40
42
45
47
49
54
55
56
58
59
60
61
63
65
67
69
72
73
78
10
12
13
19
21
32
49, 57
72
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2
Creative Solutions
You can rely on quality Allan Block products
and talented professionals to provide you creative
solutions that work. Every day, on city streets,
backyard landscapes and commercial properties,
Allan Block delivers proven performance.
Build your own creative solutions, build with
Allan Block.
®
Attend an AB Contractor Certification Training
today to learn the proper techniques to
ensure top quality retaining walls are built.
Visit allanblock.com for the latest information
as well as a complete schedule of upcoming
training near you.
Facing Series: Sierra
Color: Rustic Creek
3
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Online Resources
• Product Information
• Technical Notes
• Construction Details
• Specifications
• Testing Reports
• CADD Details
• Installation Guides
• Design Software
• Estimating Software and Apps
• Photo and Video Library
• Case Studies/Project Profiles
• Multiple Languages
• Continuing Education Credits
• Training Information and Schedules
• Testing Information
• and much more!
Available at allanblock.com
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4
Facing Series: Cascade
Color: Rustic Creek
See page 43 for
detailed information
on the AB Fieldstone
Collection.
Facing Series: Colonial
Color: Sandstone
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Facing Series: Heritage
Color: Black Hills
Environmentally Conscious
Allan Block is on the leading edge of creating a manufacturing process that leaves very little waste and can
use locally found recycled materials to produce their
latest retaining wall system.
®
The AB Fieldstone Collection is Allan Block’s solution
to a “Green/Eco-Friendly” retaining wall system while
still maintaining the beautiful look of natural stone that
is desired. This user-friendly two-piece system will revolutionize how retaining walls are made in the future.
Color: Rustic Creek
Color: Sandstone
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7
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SYSTEM
SYSTEM
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Allan Block product and wall system information.
Allan Block Products
Built-in Engineering
Gravity Walls
Reinforced Walls
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11
13
15
17
8
A Complete Family of Wall Products
The Allan Block Collections give you a choice of styles to meet your site and design requirements. Use the basic gravity
wall system for smaller wall projects. For taller wall projects use geogrid to reinforce the wall, or consider optional
techniques using masonry, no-fines, rock bolts, soil nails, or earth anchors.
AB ® Collection - Classic Cut Style
The AB® Collection has been a favorite
of wall builders for years and offers the
perfect blend of performance and style
with maximum results.
AB Europa ® Collection - Old World Antique
The AB Europa® Collection captures the
hand-laid stone effect that brings old
world charm and distinction to any project
in beautiful marbled colors.
AB Fieldstone® Collection - Green, Natural, Friendly
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The AB Fieldstone® Collection is a
“Green/Eco-Friendly” retaining wall
product that maintains the beautiful look
and feel of natural stone. Installing and
performing like our other Collections,
AB Fieldstone truly is a friendly product.
Style & Performance
Name
Setback Coverage
AB Stones
12°
COLLECTION
AB
®
Best Single Block
Choice
COLLECTION
Green, Natural & Friendly
COLLECTION
AB FIELDSTONE
®
AB EUROPA
®
Old World Antique
AB Rocks
6°
AB Vertical
3°
AB Classic
6°
AB Jumbo Jr
6°
AB Lite Stone
6°
AB Junior Lite
6°
Name
1 sq ft. approx.
11 blk per m2
1 sq ft. approx.
11 blk per m2
1 sq ft. approx.
11 blk per m2
1 sq ft. approx.
11 blk per m2
0.5 sq ft. approx.
22 blk per m2
0.5 sq ft. approx.
22 blk per m2
0.25 sq ft. approx.
44 blk per m2
Setback Coverage
AB Dover
6°
AB Palermo
6°
AB Barcelona
6°
AB Bordeaux
6°
Name
812 facing unit with SAU
1 sq ft. approx.
12 blk per m2
0.5 sq ft. approx.
22 blk per m2
0.5 sq ft. approx.
22 blk per m2
0.25 sq ft. approx.
44 blk per m2
Setback Coverage
6°
812 facing unit with LAU
6°
824 facing unit with SAU
6°
824 facing unit with LAU
6°
SAU - short anchoring unit
LAU - long anchoring unit
0.7 sq ft. approx.
16 blk per m2
0.7 sq ft. approx.
16 blk per m2
1.3 sq ft. approx.
8 blk per m2
1.3 sq ft. approx.
8 blk per m2
SYSTEM
The Allan Block Collections offer a variety of sizes, weights, setbacks, and finishes to meet differing
aesthetic and performance needs. Refer to the chart below or to our website - allanblock.com
to help make the right choice for your project.
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Table 1.1
Weight Approximate Dimensions
75 lbs
34 kg
8 in. H x 12 in. D x 18 in. L
200mm H x 300mm D x 460mm L
75 lbs
34 kg
8 in. H x 12 in. D x 18 in. L
75 lbs
34 kg
75 lbs
34 kg
35 lbs
16 kg
35 lbs
16 kg
18 lbs
8 kg
8 in. H x 12 in. D x 18 in. L
8 in. H x 12 in. D x 18 in. L
8 in. H x 9.5 in. D x 9 in. L
4 in. H x 12 in. D x 18 in. L
4 in. H x 12 in. D x 9 in. L
100mm H x 300mm D x 230mm
80 lbs
36 kg
8 in. H x 10.5 in. D x 18 in. L
40 lbs
18 kg
4 in. H x 10.5 in. D x 18 in. L
35 lbs
16 kg
20 lbs
9 kg
8 in. H x 9.5 in. D x 9 in. L
4 in. H x 10.5 in. D x 9 in. L
60 lbs
30 kg
8 in. H x 13 in. D x 12 in. L
125 lbs
55 kg
8 in. H x 13 in. D x 24 in. L
90 lbs
40 kg
185 lbs
85 kg
8 in. H x 23 in. D x 12 in. L
8 in. H x 23 in. D x 24 in. L
Actual dimensions, weights and setbacks will vary by manufacturer. Check with your local Allan Block manufacturer for exact
specifications and color availability. Caps and corner blocks are also available for each of the collections.
Patterned Walls
The design possibilities are endless. Use the blocks from the AB
or AB Europa Collections individually or blend them together to
create AB Ashlar or AB Abbey Blend patterned walls. The interlocking blocks easily fit together without any materials or tools.
AB Ashlar Blend™
from the AB Collection
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AB Abbey Blend™
from the AB Europa Collection
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The Allan Block System - Engineered For Simplicity
Allan Block’s built-in features make retaining walls easy to engineer and simple to build. These simple engineering
features make the Allan Block Collections the most efficient and reliable products on the market.
Mortarless Construction
Mortarless technology works. Building “flexible” structures with
interlocking dry-stacked materials provides superior performance
over rigid construction techniques. Add the benefits inherent in
a mortarless system - site adaptability, installation by general
laborers, lower cost - and you have what we call the
Allan Block Advantage.
Mortarless construction has been used for centuries.
Built-In Engineering
Built-In Interlock
Built-In Interlock
Every Allan Block is firmly locked in place by the patented lip and
notch configuration. No pins, no mortar, no fancy connectors.
Built-In Setback
The raised lip automatically establishes the proper setback.
Choose from 12°, 6°, or 3° systems.
Built-In Drainage
The hollow-core design combines with mortarless construction to
allow water to drain freely from behind the wall. Incidental water
moves easily through a vertical drain that is formed by the layer
of wall rock placed behind the block and in the block cores. The
dry-stack construction technique allows the incidental water to
escape by flowing around the blocks and out the wall face. This
built-in drainage helps to eliminate water pressure. Please note
that this area is not to be used as a primary water management
element.
Built-In Drainage
11
Built-In Setback
12º
6º
3º
approximate setbacks
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SYSTEM
Hollow-Core System
Allan Block’s exclusive hollow-core product design provides
many benefits over solid systems.
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• Superior drainage.
• Faster drying in wet environments.
• Better resistance to freeze-thaw cycles.
• Improved efflorescence control.
• Easier handling, faster installation, lower labor costs.
• Block-to-block interlock created from wall rock in the blocks.
• Lower production and freight costs.
Table 1.2
Standard Product Specifications
Compressive Strength
3000 psi
20.67 MPA
Absorption Northern Climates
7.5 lb/ft3
120 kg/m3
Unit Density - Hollow
125 lb/ft3
2002 kg/m3
Absorption Southern Climates
Unit Shear Strength
Reference ASTM 1372
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10 lb/ft3
645 lb/ft
160 kg/m3
9406 N/m
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Gravity Walls
A retaining wall that relies solely on it’s own weight to stand up is called a gravity wall. Allan Block combines the basic
engineering principles of setback, leverage and total unit mass with simple mechanics to make highly stable gravity walls.
Setback & Sliding Wedge
Every retaining wall supports a “wedge” of soil. The wedge
is defined as the soil which extends beyond the failure
plane of the soil type present at the wall site, and can be
calculated once the soil friction angle is known. As the
setback of the wall increases, the size of the sliding wedge
is reduced. This reduction lowers the pressure on the
retaining wall.
See references 1, 8, 18
Leverage and Total Unit Mass
As the setback of a gravity wall increases, the leverage from course to course increases.
This added leverage allows you to build taller walls before reinforcement is needed.
With the hollow core design, Allan Block comes to the job site weighing less than solid,
heavy block. Once the cores are filled, the Allan Block units develop the same unit
mass as solid blocks. This mass combines
with the setback to determine the
maximum gravity wall heights.
See Table 1.3.
See reference 1
Allan Block’s 12⬚ (Ref) system can
achieve wall heights up to 5.5 ft.
(1.7 m) without reinforcement in good
soils with a level slope above.
Gravity Wall Heights
Use the gravity wall chart
to find the maximum height
that can be built before
reinforcement is required.
The gravity wall heights
shown do not account for
seismic loading. Check
with a local engineer for
assistance if you are in a
seismic area.
See reference 1, 7
Maximum Wall Heights - AB Gravity Walls
Condition above
retaining wall
Level
Surcharge*
100 psf
(4.7 kPa)
Slope 3:1
3
1
Soil
Type
Friction
Angle
Clay
27°
Silty Sand
32°
Sand/Gravel
36°
Clay
27°
Silty Sand
32°
Sand/Gravel
36°
Clay
27°
Silty Sand
32°
Sand/Gravel
36°
12° (Ref)
AB Stones only
of AB Collection
3 ft. 6 in.
1.0 m
5 ft. 4 in.
1.6 m
6° (Ref)
AB and Europa
Collections
3 ft. 2 in.
0.9 m
4 ft. 7 in.
1.4 m
6° (Ref)
AB Fieldstone
Short Anchoring
Unit (SAU)
3 ft. 7 in.
1.1 m
5.0 ft.
1.5 m
Table 1.3
6° (Ref)
AB Fieldstone
Long Anchoring
Unit (LAU)
3° (Ref)
AB Vertical only
of AB Collection
8 ft. 6 in.
2.6 m
3 ft. 9 in.
1.1 m
5 ft. 10 in.
1.8 m
2 ft. 11 in.
0.9 m
5 ft. 10 in.
1.8 m
5 ft. 2 in.
1.6 m
5 ft. 8 in.
1.7 m
9 ft. 8 in.
3.0 m
4 ft. 3 in.
1.3 m
3 ft. 10 in.
1.2 m
3 ft. 1 in.
0.9 m
3 ft. 7 in.
1.1 m
7.0 ft.
2.1 m
2 ft. 4 in.
0.7 m
1 ft. 8 in.
0.5 m
1 ft. 4 in.
0.4 m
1 ft. 8 in.
0.5 m
4.0 ft.
1.2 m
1 ft. 1 in.
0.3 m
4 ft. 6 in.
1.4 m
3 ft. 6 in.
1.0 m
4 ft. 2 in.
1.3 m
8.0 ft.
2.4 m
2 ft. 6 in.
0.8 m
4 ft. 8 in.
1.4 m
4 ft. 1 in.
1.2 m
4 ft. 4 in.
1.3 m
7 ft. 4 in.
2.3 m
3 ft. 2 in.
0.9 m
2 ft. 8 in.
0.8 m
5 ft. 10 in.
1.8 m
2 ft. 4 in.
0.7 m
4 ft. 7 in.
1.4 m
2 ft. 8 in.
0.8 m
5 ft. 1 in.
1.5 m
4 ft. 4 in.
1.3 m
8 ft. 7 in.
2.6 m
2 ft. 1 in.
0.6 m
3 ft. 9 in.
1.1 m
Table 1.3 is based on Clay soil having an internal friction angle of 27° (Ref) or better and a Sandy soil having an internal friction angle of 32° (Ref) or better and a Sand/Gravel soils having an internal friction angle of 36° (Ref) or better. All heights based on exposed wall heights and include a cap block.
The gravity wall heights shown above do not account for seismic loading. Check with a local engineer for assistance if you are in a seismic area. Final
designs for construction purposes must be performed by a local registered Professional Engineer, using the actual conditions of the proposed site. *The
Surcharge loading category above assumes a solid surface such as concrete, asphalt or pavers having a suitable supporting subgrade.
13
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Analyze a gravity wall with the following site conditions:
Soil Type = Mixed Silts
Bearing Capacity ( S) = 3000 lb/ft2 (143,640 Pa)
(␾) = 30°
Wall Density (␥w) = 130 lb/ft3 (2,061 kg/m3)
Wall Height (H) = 3.44 ft (1.05 m)
Soil Density (␥S) = 120 lb/ft3 (1,923 kg/m3)
Batter = 12°
Factored Friction Angle (␾w) = 0.66␾
Depth of Wall (d) = 0.97 ft (0.3 m)
Slope Above Wall (i) = 0 Surcharge = None
SYSTEM
Sample Calculation
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Sliding Resistance
FA = Active force on wall = 0.5 (␥S) (KA) H2 = 156 lb/ft (2,295 N/m)
KA = Active pressure coefficient
CSC (␤) SIN (␤ ␾)
2
KA = (SIN (␤ + ␾W))1/2 + SIN (␾ + ␾W) SIN (␾ i) 1/2
= 0.2197
SIN (␤ i)
[
(
)]
W = Total weight of wall = ␥w (H) (d) = 434 lb/ft (6,639 N/m)
FV = Vertical force on wall from retained soils = FA SIN (␾W) = 53 lb/ft (785 N/m)
FH = Horizontal force on wall from retained soils = FA COS (␾W) = 147 lb/ft (2,157 N/m)
FR = Force resisting sliding = (W + FV) TAN␾ = 281 lb/ft (4,130 N/m)
Safety factor against sliding: SFS = FR = 281 lb/ft (4,130 N/m) = 1.91 1.5 OK
FH 147 lb/ft (2,157 N/m)
Overturning Resistance
MO = Overturning moment = FH (0.33) H = 168 ft. lb/ft (754 N-m/m)
MR = Moment resisting overturning = (W) [d/2 + 0.5 (H) TAN (90° ␤)]
+ (FV) [ d + (0.33) (H) TAN (90° ␤)] = 436 ft. lb/ft (1,945 N-m/m)
Safety factor against overturning:
SFO = MR = 436 ft. lb/ft (1,945 N-m/m) = 2.6 1.5 OK
Mo 168 ft. lb/ft (754 N-m/m)
See the Allan Block Engineering Manual for more information.
Bearing Capacity
W
= Pressure exerted on soil below base block
= (W + FV) / d = 487 lb/ft2 (23,847 Pa)
= 3000 lb/ft2 (143,640 Pa)
Safety factor against bearing failure:
FSB = S = 3,000 lb/ft2 (143,640 Pa) = 6.16 2.0 OK
487 lb/ft2 (23,847 Pa)
W
S
Gravity Wall Analysis
Before you analyze any retaining wall make sure you have an accurate picture of the job site conditions. Every
retaining wall must be engineered to withstand the pressure from the soils and other loads behind and above them.
Standard gravity wall analysis considers sliding, bearing and overturning forces. On sites with slopes or surcharges, a
global stability check will also be necessary.
Sliding
Ability of the structure to
overcome the horizontal
force applied to the wall.
Bearing Capacity
Factor of safety = 1.5
Overturning
Global Stability
Ability of the structure to
overcome the overturning
moment created by the
rotational forces applied to
the wall.
OTHER CONSIDERATIONS: • Slopes • Surcharges • Terraces
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Ability of the underlying
soil to support the weight
of the structure.
Ability of the internal
strength of the soil to
support the complete soil
mass. Contact local
design specialist for help
in evaluating your site.
See reference 1
14
Reinforced Soil Walls
Concept
When wall heights exceed those listed in the gravity wall chart
on page 13, geogrid can be added to provide a stable wall
condition. Layers of geogrid inserted between the blocks and
extending behind the wall interlock with the surrounding soil to
create a cohesive soil mass. This mass uses its own weight and
internal shear strength to resist both the sliding and the
overturning pressures from the soil being retained. The wall rock
in the Allan Block cores provide a positive connection between
the layers of geogrid and the Allan Block wall, locking the two
systems together. The reinforced soil mass becomes the
structure and the Allan Block wall becomes the facing. The
specific location and embedment length of the grid layers
depends upon the site conditions, wall heights and Long-Term
Allowable Design Strength of the grid being used. See the
approved plans for exact geogrid locations or consult with a
local engineer.
The Great Wall of China, dating back some 2,200 years,
was built as a double sided retaining wall. The soil
between the two walls was a mixture of clay and gravel
reinforced with Tamarisk branches. Allan Block retaining
walls employ “old technology with new materials.”
Geogrids
Geogrids are flexible, synthetic meshes which are manufactured
specifically for slope stabilization and earth retention. These
“grids” are available in a variety of materials, sizes and strengths.
They can be made of high tensile strength plastics or woven
polyester yarns and are typically packaged at the factory in rolls.
The grids are rated by Long-Term Allowable Design Strength
(LTADS) with values ranging from 500 to 4,000 pounds per linear
foot (7.3 kN/m to 58.4 kN/m).
See reference 1
Positive Interlock
Allan Block’s gravel filled hollow core provides a multi-point
interlock with the grid. As wall heights increase, our exclusive
“Rock-Lock” connection, combined with the weight of the
Allan Block units, provides the best block-to-grid interlock of any
system on the market. See the tech sheets on connection
testing or the Seismic Testing Executive Summary for testing
results on the “Rock-Lock” connection. Connection strength
testing has been done with our grid manufacturers for results see
the AB Spec Book or AB Engineering Manual.
See reference 1, 2, 3, 13
15
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SYSTEM
Analysis
External Stability
External stability exists when the entire wall system - the Allan
Block facing units and the reinforced soil mass - act as a coherent
structure to satisfy standard gravity wall analysis. Proper wall
design must satisfy all four of the following considerations.
Sliding
Bearing
Overturning
Internal Stability
Internal stability is the ability of the reinforcement combined with
the internal strength of the soil to hold the soil mass together and
work as a single unit.
Grid Rupture
Pullout
Increase grid strength
or the number of grid
layers
Increase embedment
length
Rupture occurs when
excessive forces exceed
the ultimate tensile
strength of the geogrid.
See reference 1, 12, 17
Pullout results when
grid layers are not
embedded a sufficient
distance beyond the
failure plane.
Bulging
Bulging occurs when
horizontal forces
between the geogrid
layers causes localized
rotation of the wall.
Increase number of
grid layers
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Global
Internal Compound Stability
Slip plane that runs through the
retained and reinforced
soil and wall facing.
Internal Compound
Internal Compound instability
occurs when a slip arc passes
through retained soil,
reinforced soil, and facing.
Increase length, strength,
or decrease spacing of
grid, use select infill
material
Design Considerations
• Grid strength Select the right strength grid for the job.
Choose LTADS grids from 500 lb/ft to 4000 lb/ft
(7.3 kN/m to 58.4 kN/m).
• Embedment length Grid length must extend far
enough behind the wall to create a sufficient
reinforced gravity mass. Typically a minimum of 60%
of total wall height.
AB Geogrid Wall Typical Section
• Number of layers Install enough layers to adequately
increase the internal strength of the soil mass and
handle all applied loads.
• Spacing between layers Grid layers must be correctly
spaced to distribute internal forces. Typically spaced
on 16 in. (405 mm) centers.
• Connection strength Block and geogrid must work
together to resist internal forces.
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16
Masonry Reinforcement
Allan Block retaining walls can be reinforced with the same proven
techniques used for conventional masonry walls. Allan Block
masonry walls are useful on sites where geogrids are not feasible or
cost effective because they rely on a reinforced footing and
vertical pilasters to counteract lateral earth pressures. These walls
combine the mortarless stability of an Allan Block wall with the
tensile strength of the steel rods in pilasters and the stability of the
footing. The design and construction of these walls meet all
building code requirements, while factoring in the benefit of an
inclined Allan Block wall. The specific design requirements depend
on site and soil conditions, and wall heights.
Typical Section
See reference 11
When considering special applications, unusual job sites, or
unique reinforcement requirements, contact the Allan Block
Corporation for engineering and design support.
The Allan Block Engineering Department provides assistance
to engineering and design professionals worldwide. For
additional information and case studies call 800-899-5309.
Other System Options
In addition to basic masonry wall systems, Allan Block can
accommodate special reinforcement systems such as no-fines
concrete, rock bolts, earth anchors and soil nailing.
Earth Anchor
See page 30-31 for more information on No-Fines Concrete and
installation information.
No-Fines Concrete (NFC Backfill)
Soil Nailing
17
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PLAN/DESIGN
PLAN / DESIGN
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Plan and Design an Allan Block project.
Develop a Plan
Design Evaluation
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19
22
18
Plan
Develop an accurate understanding of the job site before beginning any design, engineering, or construction on a project.
Site Geometry
Develop an accurate PLAN of existing physical features. Observe the soil type and condition, site geometry at the wall
location and immediate surroundings. Note the natural drainage patterns. Identify all physical features surrounding the
proposed wall location. Note key elevations, lot lines, utilities, structures, vegetation, etc. Conditions above and behind
the wall will determine how high the wall can go before reinforcement is needed.
Note the site geometry above and below the proposed wall location.
Soils
• Soil conditions behind and below each retaining wall have a
direct effect on the strength needed in that retaining wall.
The pressure from behind the wall will vary substantially
depending on the soil type. In general, a wall built in clay soils
will require more reinforcement than a wall of the same height
built in free draining sand or gravel soils.
• Check the soil type and conditions at the base of each wall
for adequate bearing pressure. The soil below a wall needs to
be strong enough to support the weight of the wall resting on
it. When moisture is present, extra precautions may be
required to provide a stable base.
• If the soils at the base of the wall have been disturbed - i.e.
excavated and replaced - it is imperative that these soils are
properly compacted before construction begins. It may be
necessary to remove poorly compacted or soft, wet organic
soils at the base and replace them with stable, wellcompacted soils prior to wall construction.
See page 32 & 33.
19
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Soil
Type
Clay
Mixed Soils
Friction
Angle
(Ref)
27°
32°
Sand/Gravel 36°
Soils
Table 2.1
Bearing
Equivalent
Capacity Fluid Pressure
2,500 lb/ft2
119.700kPa
50 lb/ft3
7.9kN/m3
4,000 lb/ft2
191.520kPa
30 lb/ft3
4.7kN/m3
3,500 lb/ft2
167.580kPa
35 lb/ft
5.5kN/m3
Use the soil classification chart above to identify
the basic properties of the soil at the site. These soil
properties are approximate. For a thorough soil
analysis, have a qualified geotechnical engineer
conduct a site inspection.
Water Management
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Grading
Develop a grading plan that routes water around the walls as
much as the site will allow. Provide swales above and below
the wall as required to accommodate water movement. Divert
sources of concentrated water flow from the wall. Retaining
wall designs must prevent the pooling of water above or
below the wall.
Drainage
Proper drainage planning considers water flow and volume
above, below, and behind the retaining wall.
• Most Allan Block gravity walls (lower unreinforced walls) will
drain adequately on their own.
• If a large area sheds water to the wall (i.e., parking lot),
added drainage will be necessary.
• Concentrated sources of water must be planned for
and managed.
• Reinforced walls will need added drainage for the backfill
zone and the wall base.
• Major wall structures, roadway and municipal projects, and
walls built in extreme rainfall or wet environments will need
a thorough hydrology analysis prior to construction.
Surcharges
Any added weight above the wall is called a “surcharge”.
Parking lots, swimming pools, and driveways are common
surcharges. Light duty surcharges are designed at 100 psf
(4.7 kPa). Heavier commercial surcharges (like trucks), run
250 psf (12 kPa) and up. More concentrated line loads may
also be a factor (such as building foundations). Engineering
is required in each situation.
Surcharges
• 100 psf (4.7 kPa)
Light Vehicle
• 250 psf (12 kPa)
Roadway
See reference 1
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20
PLAN/DESIGN
Make a careful observation of the general drainage patterns at
the site. Note the amount of area above the wall which will shed
surface runoff toward the wall. Note the type of surface (i.e.,
paved surfaces, sodded areas, etc.) to determine the water flow
and volume. Note any concentrated sources of water flow such
as runoff from parking lots, roof drains and scuppers, drainage
swales, creek beds, ground water, etc. See page 34 & 35.
Slopes Above
Slopes Below
Slopes
Slopes are measured “run to rise”. A three-to-one slope
goes back 3 and up 1.
Slopes Above
Slopes above the wall add more pressure and will
require more mass to resist movement. Engineering
is required.
Slopes Below
Slopes below the wall may create an unstable foundation.
Check with local building codes for length of bench that
may be required. Engineering is required.
Setback
Setback
The amount the wall leans into the hill is called “setback”.
AB units come in multiple setbacks. Bigger setbacks provide
better leverage and require less reinforcement. For taller walls
use a story pole and level to check for proper setback. Setbacks
increase when walls are built with radii. Comply with construction
tolerances which are found in the AB Spec Book or approved
construction plans.
Note: Walls designed with a 12° (Ref) setback require more space
Setback
than 6° (Ref) or 3° (Ref) systems, but will be more stable. You
may give up ground, but the final factors of safety are higher.
AB Setback Chart
AB Stones only
of the
AB Collection
AB, AB Europa (excluding
AB Stones & AB Vertical)
and
AB Fieldstone Collection
Global Stability
Global stability is an engineering analysis of the overall
balance of a slope or hillside. Walls built on hillsides may
affect this balance and stability. Cuts into a hillside will steepen
the effective slope and shift the balance of the hill, thereby reducing stability. Walls built on top of slopes have the same
effect. Engineering is required.
AB Vertical only
of the
AB Collection
6 ft
1.8 m
8 ft
2.4 m
• Slopes
• Soil Properties
• Water
allanblock.com
10 ft
3.0 m
10.0 in
15.0 in
255 mm 380 mm
20.0 in
25.0 in
510 mm 635 mm
5.0 in
7.50 in
125 mm 190 mm
10.0 in
12.5 in
255 mm 320 mm
2.5 in
65 mm
5.0 in
6.25 in
125 mm 160 mm
Global Stability
• Surcharges / Terraced Walls
21
1.2 m
3.75 in
95 mm
All values are provided for reference only.
What to consider when assessing global stability:
See reference 1, 18
4 ft
Wall Height
Table 2.2
Design
allanblock.com
Proper retaining wall design requires evaluation of the following:
• Minimize soil excavation and backfill.
• Optimize grading and drainage patterns.
• Consider existing site features.
1. Select the wall location
•
•
•
•
Calculate the wall height at its tallest position.
Identify slopes above and below the wall.
Evaluate surcharges from vehicular or construction traffic.
Select the appropriate wall batter or setback.
2. Determine wall height and geometry
3. Evaluate structural requirements
• Check the gravity wall table on page 13 for reinforcement
requirements.
• If geogrid is required, see pages 71-72 for approximate
grid length.
• For projects that fall beyond the scope of the tables in
this manual, refer to the Allan Block Engineering Manual and
contact a qualified engineer.
4. Calculate the total wall structure
• Use Table 2.2 to calculate the total wall setback.
• Add the required grid lengths to determine total wall
envelope.
• Cross check the total wall envelope with available space
at wall site.
Note: For more information see the Checklist in the AB Spec Book.
Material and Site Checklist Prior to Construction
Building a reinforced retaining wall requires advanced planning
and careful layout at the job site.
Check Your Materials
• Cross check the block delivered for color, style and setback, and
confirm it matches the AB unit specified on the approved plans.
• Cross check the geogrid delivered for strength, weight, roll size,
strength direction and manufacturer, and confirm it matches
the grid specified on the engineered plans.
Delivery and Storage
• Lay out a storage area for the block, geogrid reinforcement,
and wall rock. Store blocks on wood pallets and keep the geogrid dry, covered and clean.
• Protect the materials from damage or from coming in contact
with mud, wet concrete, and other contaminating materials.
Damaged material should not be incorporated in the project.
allanblock.com
22
PLAN/DESIGN
The design process for a segmental retaining wall typically has a
Wall Design Engineer or Site Civil Engineer responsible for the wall
design envelope. Geotechnical engineers should be hired to
evaluate the overall stability of the site. For information into the
basic concepts behind an Allan Block retaining wall design see
Design Methods section of the AB Spec Book and Best Practices
for SRW walls.
Wall Rock
The proper placement of the wall rock serves several purposes:
• Locks the block and grid together to form a “Rock-Lock”
connection.
• Increases the overall weight of each AB Unit, increasing
structural stability.
• Facilitates the compaction process in and around the blocks.
• Prevents settlement directly behind the block, which minimizes
additional forces on the grid.
Backfill Soils
• Wall Rock can be used for the base material,
within the AB Block cavities and behind the block.
• Wall Rock must be compactible aggregate
• On-site soils can be used for backfill around the geogrid
reinforcement only if they meet or exceed the design
specifications in the approved plans.
• Heavy expansive clays or organic soils shall not be used in the
reinforced zone.
• Where additional fill is required, the contractor shall submit
a sample to the wall design engineer or the on-site soils
engineer for compliance with the approved plans.
ranging in size from 0.25 in. to 1.5 in. (6 mm 38 mm) with no more than 10% passing the #200
sieve with a minimum density of 120 lbs/ft3
(1,923 kg/m3). There needs to be a balanced
mix of the sizes to achieve good compaction.
Foundation Soil Preparation
• Foundation soil shall be excavated as dimensioned on the
plans and compacted to a minimum of 95% of Standard
Proctor prior to placement of the base material.
• Foundation soil shall be examined by the on-site soils engineer
to ensure that the actual foundation soil strength meets or
exceeds assumed design strength. Soil not meeting the
required properties shall be removed and replaced with
acceptable material.
Geogrid Layout
• The geogrid reinforcement design will determine the depth of
the reinforced zone and the excavation required. Before
construction begins, verify top of wall (TW) and bottom of
wall (BW) locations. Check for buried utilities and other
obstructions in the reinforced zone.
Wall Elevation - to identify grid locations
23
allanblock.com
Refer to the AB Engineering Manual, Best
Practices for SRW Walls, AB Spec Book,
AB Seismic Executive Summary, and the
AB Walls Software for more detailed
information. For design assistance contact
the AB Engineering Department or go
to allanblock.com.
Wall Cross Section
BUILD
BUILD
allanblock.com
Installation details for Gravity or Reinforced retaining walls
for Allan Block’s AB and AB Europa Collection.
No-Fines Concrete Backfill
Working with Soils
Compaction
Water Management
allanblock.com
25
26
30
32
33
34
24
Step 1: Site Prep and Excavation
• Remove surface vegetation and organic soils.
• Per the approved plan, excavate base trench a minimum of 24 in.
•
•
•
Gravity Wall Typical Cross Section
(610 mm) wide and 12 in. (300 mm) deep.*
Remove unsuitable soils and replace with compactible materials.
Buried block should be a minimum of 6 in. (150 mm). Check plans to
see how much buried block is required.
Compact and level trench.
Step 2: Install Base Material
• Per the approved plans, place a minimum of 6 in. (150 mm) of wall
rock in the base trench and rake smooth.*
• Compact and level base material.
• Site Soils Engineer should verify that a proper base is established.
Step 3: Install Base Course
• Begin at the lowest wall elevation. Place all units top side up with the
•
raised front lip facing up and in the center of the base material.
Check and adjust for level and alignment of each unit.
Drain pipe is required for walls over 4 ft. (1.2 m) tall or are constructed in
silty or clay soils. See approved plans for location and specifications.
Refer to page 65 for details on an alternate drain location.
Step 4: Install Wall Rock and Backfill Materials
• Fill the hollow cores and a minimum of 12 in. (300 mm) behind the wall
•
•
with wall rock.
Use approved soils to backfill behind the wall rock and in front of the
base course.
Use a plate compactor to consolidate the area behind the block.
Compact in lifts of 8 in. (200 mm) or less.
Gravity Wall Base Course Cross Section.
Step 5: Install Additional Courses
• Remove all excess material from the top surface of AB units. This can
•
•
•
•
•
•
be done when installing the next course of block, by sliding the block
into place.
Stack the next course of blocks so that the vertical seams are
offset from the blocks below by at least 3 in. (75 mm) or 1/4 the
length of the block.
Check and adjust for level, alignment and the wall batter as the wall
stacks up.
Fill the block cores and behind the block with wall rock a minimum of
12 in. (300 mm). Use approved soils to backfill behind the wall rock.
From course 2 and above use a plate compactor to compact directly
on the blocks as well as the area behind the blocks. Compact in lifts
of 8 in. (200 mm) or less.
Complete wall to required height. See page 55 for information on wall
ending options.
Use 8 - 12 in. (200 - 300 mm) of low permeable fill on the last lift to finish
off wall.
* For walls under 4 ft. (1.2 m), an 18 in. (460 mm) wide by 10 in. (250 mm)
deep trench with 4 in. (100 mm) of wall rock base material is acceptable.
25
allanblock.com
Compact
Base Material
Level
Install base material, level and compact.
Level
String
Line
Adjust
with a
dead
blow
hammer
Level blocks, adjust where needed.
Step 1: Site Prep and Excavation
allanblock.com
BUILD
Foundation soils at the bottom of the base trench must be firm and solid.
If the soils are made up of heavy clay or wet soils, or the areas have been
previously excavated, remove entire material and replace with granular
base, compacting in 8 in. (200 mm) lifts or less.
• Remove all surface vegetation and organic soils. This material should
not be used as backfill.
• Excavate behind the wall to accommodate the design length of the
geogrid. Refer to the approved plans for exact length.
• Excavate base trench at the wall location. Dig the trench, per the
approved plans, a minimum of 24 in. (610 mm) wide and 6 in. (150 mm)
deep plus the required amount to accommodate the buried block.
• Buried block should be a minimum of 6 in. (150 mm) or 1 in. (25 mm) for
each 1 ft. (300 mm) of wall height. See approved plans for exact
amount needed.
• Compact and level base trench to 95% of Standard Proctor.
Reinforced Wall Base Course
Cross Section.
Step 2: Install Base Material
The base material can be any compactible granular material. Allan Block
recommends a well-graded aggregate, with a balanced mix of grain
sizes, ranging from 0.25 in. to 1.5 in. (6 mm to 38 mm) diameter.
• Per the approved plans, place drain pipe at the back of the trench the
length of the wall. The drain pipe will need to be vented to daylight or to
a storm sewer system. See approved plans for location and specifications.
• Per the approved plan, place a minimum of 6 in. (150 mm) of base
material in the base trench and rake smooth.
• Compact with a mechanical plate compactor.
• Check the entire length for level, and adjust as needed.
Level
Compact
base
material
Install and compact base material.
Typical Reinforced Wall Cross Section
Reinforced Wall Structure
Reinforced Zone
The reinforced zone is located directly behind the block in two
sections, the consolidation and the compaction zone. Both zones
require compacting in maximum lifts of 8 in. (200 mm), to 95%
Standard Proctor. Refer to the specifications in the approved plan
for compaction requirements in these zones for each project.
Consolidation Zone
The consolidation zone runs from the back of the block back 3 ft.
(0.9 m) into the infill soil. Only mechanical plate compaction
equipment shall be allowed within the consolidation zone.
Compaction Zone
The compaction zone runs from the back of the consolidation zone
to the cut in the slope. Heavier compaction equipment can be used
in this zone provided no sudden braking or sharp turning occurs.
allanblock.com
26
• Begin at the lowest wall elevation.
• Place all units top side up with the raised front lip facing up and in the
•
•
•
center of the base material.
Check and adjust for level and alignment of all AB units. Check block
for level frequently from side-to-side and front-to-back. Verify the
proper position of all AB units by examining a string line across the
back of the blocks or by sighting down the back of the raised front lip.
Make minor adjustments by tapping the AB units with a dead blow
hammer or by placing up to 0.5 in. (13 mm) of coarse sand under
the units.
Irregularities in the base course become larger as the wall stacks up.
Careful attention to a straight and level base course will ensure a
quality finished wall.
Step 4: Install Wall Rock and Backfill Material
• Fill the hollow cores of the base course and 12 in. (300 mm) behind the
•
block with wall rock. A compactible aggregate ranging in size from
0.25 in. to 1.5 in. (6 mm to 38 mm) in diameter, and containing less
than 10% fines is recommended.
Use approved infill soils to backfill behind the wall rock and in front of
the base course.
Step 5: Compact
Compaction of the material behind the block is critical for a quality wall.
• Use a mechanical plate compactor to consolidate the wall rock, then
compact the backfill material immediately behind the block. Compact
in a path parallel to the wall, working from the back of the block to the
back of the backfill material See page 33 for additional details on
compaction.
• Check the base course for level and adjust as necessary.
• All backfill soils must be compacted to a minimum 95% Standard
Proctor. Use equipment appropriate for the soil being compacted.
• Remove all excess material from the top surface of all AB units. This
prepares a smooth surface for placement of the next course. This can
be assisted when installing the next course of block, by sliding the
block into place.
• Every course after the first course requires compaction starting on the block.
Stepping Up The Wall Base
Walls built on a sloping grade require a stepped base.
• Begin excavation at the lowest point and dig a level trench into
the slope until it is deep enough to accommodate the base
material and one entire block.
• At this point step up the height of one block, and begin a new
section of base trench.
• Continue to step up as needed to top of slope.
• Always bury at least one full unit at each step.
27
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Level
String
line
Adjust with a
dead blow
hammer
Install base course.
Infill
soils
Wall
rock
Fill void in
front of
block
Install wall rock.
Compact
parallel
to wall
Compact wall rock and backfill soils.
Step 6: Install Geogrid
allanblock.com
Pull back geogrid
and stake in
place
Place cut
edge of grid
tight against
front lip
Install geogrid, stake in place.
Set second
course on
top of
geogrid
Working With Geogrid
Geogrid typically comes in large rolls up to 13 ft (4 m) wide and 250 ft (76 m) in length. These “grids” also come in a variety of weights and strengths. Taller walls often require heavier strength grids, especially in the bottom portions of the wall.
It is critical that the correct grid is installed in the wall. Check the engineered plans and specifications.
Most grids are strongest along the roll or machine direction. Reinforced grid designs require that all grids are placed with
the machine direction running from the face of the wall towards the back of the excavation area.
See page 58-60 for information on using grid with corners and curves.
Machine or
roll direction
Install geogrid with
the machine or roll
direction running
from the block
back into the
reinforced
zone.
Use a pair of
grid stands to
help measure
and cut geogrid
to required
lengths.
Front of wall
Machine or
roll direction
allanblock.com
28
BUILD
Refer to the plans for placement of grid; this example starts on the base course.
• Cut sections of geogrid to specified lengths. Check manufacturer’s
grid specifications for strength, and roll or machine direction. Refer to
the approved plans for exact size and location.
• Install the layer of geogrid by placing the cut edge to the back of the
raised front lip and roll the layer out to the back of the excavation
area. The excavation area must be fully compacted and level.
• Stack the next course of block on top of the geogrid, so that the blocks
are offset from the blocks below. Each new course should be positioned
so that the vertical seams are offset by at least 3 in. (75 mm) and are tight
against the front edge of the units below. Perfect running bond is not
required.
• Sight down the wall line to check for a straight wall. Blocks may be
adjusted slightly to form straight lines or smooth flowing curves.
• Pull on the back of the grid to remove any slack. Stake in place
before installing wall rock and approved infill soils.
Step 7: Backfill and Compact
• Install wall rock in block cores and 12 in. (300 mm) behind wall. Use
approved infill soils to backfill behind the wall rock in the reinforced zone.
Compact in 8 in.
(200 mm) lifts
• All wall rock and infill soils within 3 ft. (0.9 m) of the wall must be
•
•
•
•
properly compacted using a mechanical plate compactor. Compact
in maximum 8 inch lifts (200 mm), this time starting on the block and
working in a path that runs parallel to the block towards the back of
the reinforced zone. Compact all materials to a minimum 95%
Standard Proctor.
Never operate compaction equipment directly on geogrid.
All heavy equipment must be kept at least 3 feet (0.9 m) from the back of
the wall. Wall designs typically do not account for surcharges from heavy
compaction equipment. Even a properly installed and compacted wall
will rotate forward when extreme surcharges from heavy equipment are
applied to the top of the wall during construction and final grading.
stacks up. It is acceptable to shim under blocks to compensate for a
build up of tolerances or an out of level base condition. Asphalt shingles
or geogrid work well when shims are required. The maximum allowable
shim thickness per course is 1/8 in. (3 mm).
Remove all excess wall rock and ridges or slag material from the top
surface of all AB units. This prepares a smooth surface for placement
of the next course. Plate compactors operated on top of the block
will remove most slag material and prep the block for the next course.
When installing the next course of block, sliding the block into place
will also remove any slag material.
Compact in 8 in. (200 mm) lifts.
Keep heavy
equipment
3 ft. (0.9 m)
from back of
block
Keep heavy equipment away from the
back of the block.
Sight down
edge
• Repeat steps 6 & 7 to complete wall to height required, installing grid
•
•
where needed per the approved plans.
Use 8 in. (200 mm) of impermeable fill on the last lift to finish off wall.
See page 55 for information on ending and topping off the wall.
For information on Allowable Construction Tolerances see the
AB Spec Book.
29
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Install blocks
tight against
blocks below
Install additional courses.
Seams at
3 in. (75 mm)
minimum
offset
No-Fines Concrete
Use of AB No-Fines Concrete Backfill has increased our ability to install reinforced walls in locations where typical construction would
not be possible because of property line constraints or limited excavation options. When using the Allan Block products with NoFines concrete, the permeable concrete actually attaches to the
back of the block and extends the depth of the wall mass. This allows for taller walls with less excavation than conventional geogrid
reinforced walls.
allanblock.com
BUILD
Typical geogrid reinforced walls require an excavation depth of
60% or more of the wall height; while a No-Fines reinforced wall,
with similar site conditions, requires only 30 to 40% of the wall
height. The recommended minimum structure depth of the
No-Fines Concrete Backfill, measured from the face of the wall to
the back of the mass, is 24 in. (60 cm). Limiting the excavation
depth will not only save time and money, but it might make the
difference between getting the job or not.
There are additional advantages to using the No-Fines solution.
Contractors are able to build with better production rates and with
less manpower. The use of No-Fines Concrete Backfill also eliminates the need for compaction and compaction testing of the
reinforced soil. It provides superior wall drainage since the entire
mass is permeable; therefore eliminating the need for wall rock in
No-Fines Concrete (NFC Backfill)
the cores and behind the wall. This pervious concrete backfill will
provide a “solid” solution that can reduce the overall settlement
behind the wall.
Engineering Properties:
• No-Fines Concrete Backfill can be used with any of the Allan
•
•
•
•
•
Block Retaining Wall Collections.
No-Fines Concrete Backfill typically consists of cement, fly ash,
water and coarse aggregate. The quantity of cementitious
material is approximately 500 lb/yd3 (297 kg/m3) with a
water/cement ratio of approximately 0.30 – 0.40.
No-Fines Concrete Backfill is designed using 3/8 in.to 3/4 in.
(9.5 mm to 19 mm) aggregate with an aggregate/cement
ratio of 6:1.
The density of this product will vary with the density of the
aggregate used, but will typically range between 100 lb/ft3 –
135 lb/ft3 (1600 kg/m3 – 2160 kg/m3).
No-Fines Concrete Backfill has little to no slump and exerts
pressure on the soil and Allan Block wall similar to loosely
poured aggregate until cured.
When using No-Fines Concrete Backfill, the backfill zone will also
serve as the required drainage or wall rock zone within the
cores and directly behind the wall.
allanblock.com
30
No-Fines Concrete Installation Steps
Refer to the page 26 for the complete installation steps when preparing
the base trench and installing the first course of blocks. Once the first
course of blocks are installed and leveled, following these simple steps to
place the No-Fines Concrete Backfill:
• Fill all the voids in the block and backfill to the specified depth with the
No-Fines concrete. Obviously, there are numerous ways to get the
concrete mix to the back of the wall. Each site will be different.
• It is recommended, but not required; for straight wall sections, one of
the back wings of the Allan Block units be removed to help secure the
block face to the concrete backfill.
• The vertical height of a pour should not exceed 16 in. (406 mm) or two
courses of block.
• Additional pours can be made as soon as the No-Fines concrete
backfill in the previous lift has set, which is usually not longer than 2 to 3
hours. Additional courses of block could be stacked while waiting for
the backfill to cure.
Additional Courses
• Brush the top of the blocks to remove any excess material. It is
•
recommended that this be done before allowing the concrete to
harden. Install the next course of blocks ensuring that they are level.
Place the No-Fines Concrete Backfill the same way as outlined in the
previous step.
Continue these steps until the wall reaches its designed height.
Finishing Options
• Use 8-12 in. (200-300 mm) of low permeable fill on the last lift to finish off
•
•
wall. Place a layer of landscape fabric horizontally above the No-Fines
prior to placing the impermeable fill.
Place a horizontal layer of filter fabric above the no-fines mass prior to
placing low permeable fill above.
See page 55 for information on ending and topping off the wall.
Soil Types: Coarse to
medium sands, clean
sand and gravel, little
or no-fines - f = 36°
No-Fines Chart
Condition
Above Wall
Level Slope
Above the Wall
31
Wall Height
ft
4
6
8
10
m
1.2
1.8
2.4
3.0
Buried
Block
in
4
6
8
10
cm
10
15
20
25
12° (Ref)
AB Stones only
of the
AB Collection
ft
2
2.5
3.5
m
0.7
0.8
1.1
Excerpt from Table 6.2 shown on page 71.
Soil Types: Uniform to
well graded sands,
silty sands - f = 32°
Depth of No-Fines including wall facing
6° or 3° (Ref)
AB, AB Europa and
AB Fieldstone
Collections
(Excl. AB Stones)
ft
2.5
3
4
Soil Types: Sand-SiltClay mix, Clayey
sands - f = 27°
m
0.8
1
1.3
12° (Ref)
AB Stones only
of the
AB Collection
ft
2
2.5
3.5
allanblock.com
m
0.7
0.8
1.1
6° or 3° (Ref)
AB, AB Europa and
AB Fieldstone
Collections
(Excl. AB Stones)
ft
2.5
3.5
4
m
0.8
1.1
1.3
12° (Ref)
AB Stones only
of the
AB Collection
ft
2
2.5
3.5
4
m
0.7
0.8
1.1
1.3
6° or 3° (Ref)
AB, AB Europa and
AB Fieldstone
Collections
(Excl. AB Stones)
ft
2
2.5
3.5
4.5
m
0.7
0.8
1.1
1.4
Working with Soils
The soils used below and behind the wall are a critical part of the
total wall structure.
A reinforced retaining wall is a structure containing three basic
building materials - the block facing, the synthetic geogrid
reinforcing materials, and the infill materials surrounding the
geogrid layers.
Soils
Check the on-site soils carefully before beginning, and get a
written identification of the soil type. A soils report from a local
engineer will be required before a design and/or permit is issued
for most walls above 4 ft. (1.2 m). Table 3.1 provides general
classification of soils.
Soil Selection
If the on-site soils are of a very low quality, you should remove and
replace them with better backfill material in the reinforced zone
and the foundation area. The cost of removal will be offset by
reduced reinforcement, faster compaction, and better long-term
performance.
Table 3.1
Typical Friction Angle and Soil Unit Weights
Compacted to 95% Standard Proctor
Soil Type
Crushed stone, gravel
Clean sands
Silty sands/sandy silt
Sandy clay
Other soils
Soil Friction
Soil Unit
Angle
Weight (pcf)
34° +
110 - 135
32 - 34°
100 - 130
28 - 30°
110 - 125
26 - 28°
100 - 120
Determined by testing
All soil friction angles and unit weights are provided as
reference only and are subject to change based on
geographic area and site conditions.
In the reinforced zone, the type of soil used will determine the
amount of grid reinforcement needed. Heavy clays and organic
soils are both unsuitable in the reinforced zone. Generally, any soil
with a friction angle lower than 27° (Ref) or a plasticity index (PI) of
greater than 20 should be removed and replaced. Soils with friction
angles between 27° (Ref) and 31° (Ref) will require additional care,
and attention to water management when placed and compacted. This will include extra inspections by an on-site engineer.
You must use infill soils that meet or exceed those specified in the
engineered specifications and drawings. Have the soils tested
before placing and compacting.
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32
BUILD
Understanding the properties and characteristics of soils is key to
building better walls. Different soil types will dictate the amount
of time needed for compaction, the amount of reinforcement
required, and potentially the cost of the wall.
allanblock.com
Compaction
Proper placement and compaction of the infill soils are critical. Compaction is often measured as a percentage of optimum consolidation of
material being utilized. Foundation and infill soils require compaction to
95% of Standard Proctor, or 95% of the soil's maximum density. Local
geotechnical and civil engineers are trained to test and measure
compaction densities. On-site testing should be part of the wall project
and included in the bid documents. Obtaining the optimum moisture
content will ensure that the maximum density can be achieved. Soil that
is too dry or too wet will not reach 95% of Standard Proctor.
The most important step in getting proper compaction is the placement
of the soil in "lifts". Compacting in lifts, or layers, of less than 8 in. (200 mm)
will facilitate quality compaction. Compaction equipment must be sized
according to the type of material being compacted. Placement and
compaction in lifts that exceed 8 in. (200 mm) will result in less than
adequate soil strength. Consult with a local equipment supplier to ensure
that proper compaction equipment is used. Always backfill and compact after each course of block is placed.
The consolidation zone runs from the back of the block back 3 ft. (0.9 m)
into the infill soil. Only walk behind mechanical plate compaction
equipment shall be allowed within the consolidation zone. A minimum
of two passes with a walk behind plate compactor are required. Continue compaction process until proper compaction is achieved, starting
on top of the block and compacting in paths that run parallel with the
wall to the back of the consolidation zone.
Some applications require higher levels of compaction in the consolidation zone. Examples of these include additional walls or structures
located within 3 ft (0.9 m) of the back of the wall.
Higher levels of compaction can be achieved within the consolidation
zone by decreasing the lifts to 4 in. (100 mm) and compacting with walk
behind compaction equipment, starting at the wall facing and running in
paths that run parallel to the wall. Compacting in smaller lifts will achieve
higher compaction levels and will not place lateral loads on the wall
facing. Multiple passes of the compaction equipment will be required.
Higher compaction levels reduce settlement over time.
33
allanblock.com
Correct Compaction Process
Water Management
The design and performance of most retaining walls are
based on keeping the reinforced zone relatively dry. To
ensure that wall structures perform, the construction of
the wall and layout of the site must be based on
maintaining a soil moisture content that is relatively
low. Relatively low equates to the moisture content
required to achieve desired compaction.
allanblock.com
BUILD
Site civil engineering firms utilize a thorough understanding of the site to determine where water will
come from and how it will be properly managed.
Throughout their design process, sources of water are
taken into account to handle above and below
grade concentrations of water.
Contractors must understand the intent of the approved site plans and what will be required to
protect the area impacted by the wall construction.
Temporary berms may be required to direct water
away from construction sites.
Allan Block walls may be designed with an array of
details to ensure that the wall and reinforced soil
structure remain free of excess moisture. Basic design
details mandate toe drains for all walls over 4 ft.
(1.2 m) in height, with slopes, or other structures above
the wall. Once geogrid is introduced into the design,
heel drains are also incorporated. In all cases wall
rock is located within the cores of the block and a
minimum of 12 in. (300 mm) behind the block. These
three details are designed to remove incidental water
within their respective locations and are not meant as
primary drainage paths for above or below grade
water management. Refer to your approved plans or
the AB Spec Book for specific information on these items.
Typical Drain
Drains must be vented to daylight or connected to a storm sewer
system.
All drain pipes must be protected from migration of fine material.
Refer to approved plans for construction details.
See page 65 for a cross section drawing of this drain.
allanblock.com
34
Grading
During wall layout it is important to evaluate the entire site to
determine if water will drain into the area where the walls will
be constructed. Using simple berms and swales to divert the water
around the wall can be easily done. Since walls are often built before the site is completely graded to its final configuration, temporary
grading must be in place to ensure water will not be draining towards
the construction area. Contact the local engineer of record and the
site civil engineer for directions prior to proceeding with construction
of the wall.
Chimney Drain
Ground Water
Ground water can be defined as water that occurs within the soil.
Sources include surface infiltration, water table fluctuation and layers
of permeable soils. Ground water movement must be prevented
from coming in contact with the retaining wall structure, including the
reinforced soil mass.
Construction details to prevent subsurface water from coming in
contact with the retaining wall structure should be defined on the
approved plans. Use blanket and chimney drains to intercept
ground water from potentially infiltrating the reinforced mass.
When ground water is encountered during construction work with
the engineer of record to ensure that the water has been accounted
for in the design.
Extra care must be employed to prevent water from entering the
reinforced zone when non-permeable infill soils are used in wall
construction.
Blanket Drain
Drain pipes used in toe or heel drain applications must be properly
vented a minimum of every 50 ft (15 m). Methods to accomplish this
include having drain pipes draining into the storm sewer system or
vented to a lower elevation on the site. See approved plans for
locations.
When venting to a lower elevation, it is important that all drain
locations are properly marked during the construction phase and
protected during and after the completion of the project to ensure
that the drain pipe is not damaged or plugged. Rodent screens and
concrete collars are examples of details employed to allow for water
to flow through the outlet pipes and keep the pathway clear of debris.
If details are not identified on the plans, request guidance from the
local engineer or the site civil engineer.
Concentrated Water Sources
Prior to constructing the wall, review drainage plans and details with
the general contractor or site civil engineer to identify all potential
sources of concentrated water.
Examples that must be accounted for are:
• Below grade storm sewer pipes
• Water lines, mains or fire hydrants
• Grading of site
• Parking lots
• Catch basin to storm sewer system
• Roof down spouts
• Slopes above walls
35
allanblock.com
Vent Drain Pipe Option
BUILD PATTERNED WALLS
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Installation details for building patterned for Allan Block’s
AB and AB Europa Collection retaining walls.
Wall Patterns
allanblock.com
37
38
40
36
Wall Patterns
All of the Allan Block Collections can be used to create a
variety of pre-set and random patterns. A pre-set pattern
is repeated every two or three courses of block. A single
course consists of a full size block, approx 8 in. (200 mm)
tall. Random patterns used on a reinforced wall require a
level surface every 2 or 3 courses for proper installation of
geogrid. See the approved plans for which layers the
geogrid reinforcement will be required.
Note:
• Patterned walls will have a 6° setback.
• Walls with curves should always use the 2 course
pattern to minimize cutting and fitting.
• The base course needs to be a full course of full
size blocks. For each 10 ft. (3 m) length you will
need 7 blocks.
Standard Patterns - Uses all blocks in the collections
Two Course Pattern
16 in.
10 ft. (3 m)
Approx.
10 ft. (3 m)
Approx.
6
4
8
8
(405 mm)
Approx.
Three Course Pattern
24 in.
10
10
10
4
(610 mm)
Approx.
AB Collection
AB Europa Collection
AB Collection
Blocks Required
AB Classic or AB Stones
AB Jumbo Junior
AB Lite Stone
AB Junior Lite*
Blocks Required
AB Classic or AB Stones
AB Jumbo Junior
AB Lite Stone
AB Junior Lite*
6
4
8
8
Blocks Required
AB Dover
AB Palermo
AB Barcelona
AB Bordeaux
Blocks Required
10
10
10
4
AB Dover
AB Palermo
AB Barcelona
AB Bordeaux
* Note: In the AB Collection, if the AB Junior Lite is not available an AB Lite Stone will need to cut in half. See page 41 for more information.
Lite Patterns - Uses only the smaller blocks in the collections
Two Course Pattern
16 in.
10 ft. (3 m)
Approx.
10 ft. (3 m)
Approx.
24 in.
AB Collection
7 AB Jumbo Junior
15 AB Lite Stone
12 AB Junior Lite*
(405 mm)
Approx.
Three Course Pattern
AB Collection
Blocks Required
Blocks Required
14 AB Jumbo Junior
19 AB Lite Stone
18 AB Junior Lite*
(610 mm)
Approx.
Note: Maximum recommended wall height for Lite Patterns is 6 ft. (1.8 m).
For more information see the Allan Block Patterns document available at allanblock.com
37
allanblock.com
Blocks Required
7 AB Palermo
15 AB Barcelona
12 AB Bordeaux
Blocks Required
14 AB Palermo
19 AB Barcelona
18 AB Bordeaux
Step 1: Excavate and Install Base Course
Refer to page 26 for a detailed description on how to install the base course.
Basic steps include: 1) Site prep and excavation, 2) Install base material,
3) Install base course 4) Install wall rock and backfill materials, geogrid if
necessary, and 5) Compact.
Note: Full-sized blocks should always be used for the base course. This will
speed the leveling and installation of the first course.
Step 2: Install Geogrid
Refer to the plans for placement of grid; this example requires grid on top
of the base course.
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Install base
course with full
size units and
compact
Install base course and compact.
•
•
course. This prepares a smooth surface for placement of the geogrid
and the next course of blocks.
Cut sections of geogrid to specified lengths. Check manufacturer’s
grid specifications for strength and roll or machine direction. Refer to
Install the layer of geogrid by placing the cut edge up to the back of
the raised front lip and roll the layer out to the back of the excavation
area to the length specified in the approved plans.
Step 3: Install the Multiple-Course Pattern
The example shown here uses a 2 course pattern. Check the approved
plans to determine the best pattern option for the project. See page 37 for
more information on patterns.
• Stack the first course of the pattern on top of the geogrid and the base
course.
Install
Geogrid
Install geogrid.
Stake grid in
place
• Check blocks for level, and make adjustments as needed. Pull on the
back of the geogrid to remove any slack. Stake geogrid in place.
• Install wall rock in the block cores and 12 in. (300 mm) behind the
blocks. Compact using a shovel handle inside the cores. Check
blocks for level. See below for more information on compaction in
the block cores.
• Remove all excess material and slag from the top surface of the base
First course of
the pattern
Stack first course of pattern and
backfill wall rock in block cores.
Typical Reinforced Patterned Wall
Compaction on Patterned Walls
Compaction in the block cores
needs to be done regularly when
working with patterned walls. This
can be done by using the end of a
shovel to compact the wall rock,
adding additional rock if necessary.
At each 8 in. (200 mm) lift, compact
the block cores with the end of a
shovel, and the area directly behind the block with a plate
compactor per the procedures described in this manual.
At the conclusion of each pattern, the top of the wall will be level.
Run the plate compactor over the top of the blocks to consolidate
the wall rock. Place grid if required, and begin the next pattern.
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38
• Use approved infill soils to backfill behind the wall rock in the reinforced
zone. The height of the wall rock and backfill material cannot exceed
8 in. (200 mm) before compacting. The top of the blocks will not
always match up with each lift of soil.
• Using a mechanical plate compactor, compact the wall rock and infill
materials behind the wall in maximum 8 in. (200 mm) lifts. Compact
immediately behind the wall in a path parallel to the wall, working from
the back of the wall to the back of the excavated area. Compact to a
minimum of 95% Standard Proctor.
• Check blocks for level. and then install the remainder of the 2 course
pattern. Install wall rock in the block cores and behind the blocks as
before. Use approved infill soils to backfill behind wall rock. Check
blocks for level and for batter.
• With the first multiple-course pattern completed, use a plate
compactor to compact the wall rock in the block cores and the wall
rock behind the blocks. The first pass of the plate compactor should
be directly over the top of the block cores.
Compact wall
rock and backfill
materials parallel
to wall
Compact behind the wall.
• After running the plate compactor on top of the blocks and wall rock,
compact the infill material immediately behind the wall. Compact in a
path parallel to the wall, working from the front of the wall to the back
of the infill material. Compact to a minimum of 95% Standard Proctor.
Compact on
blocks first and
then the wall rock
and backfill
materials when
pattern completed
• Check and adjust for level and alignment and wall batter as the wall
build up of tolerances or an out of level base condition. Asphalt shingles
or geogrid work well when shims are required. The maximum allowable
shim thickness per course is 1/8 in. (3 mm).
Step 4: Install The Second Multiple-Course Pattern
Complete pattern and compact.
• Repeat Step 2 to install geogrid between the patterns when required
Offset
patterns
Refer to the approved plans to determine if geogrid reinforcement will be
required on the next course of the pattern being used.
per the approved plans.
• Repeat Step 3 for each pattern being installed. Each additional
pattern will need to be offset from the pattern below to avoid a
repetitive look.
Note: Keep all heavy equipment at least 3 feet (0.9 m) away from the
back of the wall.
Step 5: Ending and Topping off Wall
Completing a patterned wall is the same as for a standard wall. See
page 55 for finishing details. The only requirement is that a multiple
course pattern must be completed so that the top course of the blocks
form a level surface.
• Use 8 in. (200 mm) of impermeable fill on the last lift to finish off wall.
39
allanblock.com
Pattern
Sections
Install geogrid and additional patterns.
• For walls that require geogrid reinforcement, selection of which pattern
•
to use is determined by the grid spacing shown on the approved plans.
If grid is required every 2 courses, then use a 2 course pattern;
if 3 course grid spacing is required, use a 3 course pattern.
If building with a random pattern, the pattern must be leveled off at the
appropriate courses to allow for the installation of geogrid on a flat
surface.
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Ending Patterned Walls
Ending Patterned Walls - Step Downs
Patterned walls may be ended with step ups or turn-ins. When ending
a patterned wall, discontinue the pattern and randomly adjust as
necessary to meet the site conditions. See page 55 for more information
on ending walls.
Curves
When building curves, the 2 course pattern is easier to work with than the
3 course pattern. The 3 course pattern will require more custom fitting or
cutting of blocks to ensure a tight fit.
Inside curved walls are easily constructed by maintaining a tight spacing
at the front of the wall face. For tighter radii, it may be necessary to cut
out parts of the bottom notch in order for the blocks to fit tightly together.
See page 56.
Outside curved walls The wall will “tighten” as the height increases. There are
three methods to adjust for the tightening effect:
• On the first course of the pattern, open the spacing between blocks
slightly so that the top course(s) of the pattern will need minimal cutting.
• Reduce the lengths of the blocks by shortening them, using a saw with
a diamond blade.
• Remove parts of the bottom notch for the blocks to fit tightly together.
See page 56.
The best answer is to always use the 2 course pattern when building curves.
Dash of Ashlar
The AB Collections have been created in modular sizes to
allow for easy construction of patterned walls. Selected areas
of non-patterned walls can also contain patterns. With the
modular design, the blocks can be installed with ease.
allanblock.com
40
Corners
Outside corners are easily built using AB Corner Blocks.
• Start at the corner and build the wall working out in both directions.
• When ending a patterned wall with a corner, use a random
selection of blocks to transition from the patterned courses into
AB Corner
the AB Corner Blocks.
Blocks
Note: Always start the base course at the lowest elevation, then
beginning additional courses at the corner will minimize cutting.
Inside corners are constructed in the same manner as for
non-patterned walls.
• Remove the top lip of the course where the walls intersect.
See page 59.
Patterned Walls With Corners
Random pattern
2 course pattern
Grade
Stairs
When building steps into patterned walls, use the full-sized AB Blocks for
step blocks. See page 61 for stair construction details.
2 course pattern
Below grade
Patterned Walls With Stairs
Step-Ups
When building a wall always start the base course at the lowest elevation.
See page 27 for more information on construction.
Additional Construction Tips
• If an AB Junior Lite is needed and not available, an AB Lite Stones
•
•
41
will need to be cut to produce 2 half lite blocks. Pre-cut the desired
number of blocks to speed installation.
Offset each new pattern from the pattern below to maintain the
“random” appearance.
With walls that have numerous inside and outside curves, use a
2 course pattern to ease the installation process.
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Cutting A
Block In Half
BUILD AB FIELDSTONE
®
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Installation details for building with the AB Fieldstone retaining wall system.
allanblock.com
BUILD AB FIELDSTONE
45
47
49
42
Color: Rustic Creek
®
AB Fieldstone Collection
The First Eco-Friendly Concrete
Retaining Wall System
AB Fieldstone is an innovative new concept in the manufacture and use
of segmental retaining wall (SRW) systems. By manufacturing this system in
2 pieces - the facing unit and the anchoring unit, Allan Block has opened
the door to many benefits that are not only Green, but Natural and
Friendly as well.
Anchoring unit -available
in two universal sizes and
produced with local
recycled materials.
The facing units are created with differing textures and colors to emulate
natural stone, which are referred to as Series. There are currently four Series to choose from: Sierra, Cascade, Colonial and Heritage Series, with
additional ones in development. This product concept provides the potential for a variety of new styles and textures. Visit allanblock.com for all
the latest information.
The anchoring units are produced with local recycled materials while
maintaining a beautiful and distinctive look. Manufactured in universal
sizes to work with any of the different facing Series, this innovative new
product has unlimited possibilities.
The Dogbone units are
used to create parapets in many widths.
The parapets can be
used to finish off the
top of a retaining wall
with seating or planters
or can be built as free
standing walls.
43
See pages 52-53.
AB Dogbone unit - NEW
Facing unit - available in
different sizes and Series
styles. Each Series has
varied block faces to
ensure a random look,
just like you would see
in nature.
Some of the facing units
are manufactured with a
textured side eliminating
the need for extra blocks
when building corners or
ending walls.
AB Fieldstone retaining walls can help projects
achieve LEED® points in 14 different credits.
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AB Fieldstone comes as close as you can get to matching the raw beauty of natural stone. With the
many faces of AB Fieldstone that resembles hand-hewn limestone, chisled sandstone, and rough cut
stone to name a few the choices are sure to provide a timeless elegance to any surrounding. By
blending the Series faces together in a project it creates a way for
many more unique looks and styles.
allanblock.com
To compliment the different Facing Series available, you have a range of
colors to choose from. For cool tones choose our Glacier Bay, Sandstone,
Kasota Gold or Black Hills, for warmer earth tones choose the Rustic Creek
or Walnut or for an exciting rich red tone try our Canyon Springs.
With the Series choices and color options, this system truly has unlimited
design potential.
The AB Fieldstone Collection has everything you need for a stylish look
as well as being a recycled product. Not to mention, it also has many
“Friendly” advantages. The lighter-weight two-piece system makes it
easy to handle. With the ability to build taller gravity walls with the
same installation practices as our AB and AB Europa Collection, there is
no new installation process to learn. The exciting advantages of the
facing unit with its built-in corner and height control, where every facing unit is the exact same height, makes building with AB Fieldstone a
hassel free experience.
Allan Block is continually developing new Series looks and complimenting colors, so visit allanblock.com for the latest information. While you
are there check out our easy to use estimating tools to determine all
your material needs.
BUILD AB FIELDSTONE
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44
AB Fieldstone Gravity Wall Construction
For complete details on the proper steps for site prep, drainage requirements and installing the base material, see page 25 - Steps 1
and 2. Most designs will require a local wall design engineer or a site
civil engineer to develop approved plans. The projects must be built
to these approved plans and specifications.
Install
facing
units
• Begin at the lowest wall elevation by placing the AB Fieldstone facing units
on the base material towards the front of the trench, leaving room for the
AB Fieldstone anchoring unit so when entire assembly is installed it is
centered on the base materials. Check each unit and adjust for level and
alignment. The facing units can be randomly flipped upside down to give
different facing appearances.
• For proper placement of the AB Fieldstone anchoring units, use a brick
hammer to create a small trench to allow for the lip.
• Install the AB Fieldstone anchoring units into the receiving slots of the
facing units with the lip facing down in the trench just created. Make
adjustments to ensure anchoring units are installed reasonably level with
the facing unit. The anchoring units should never be installed higher
than the facing unit. Except for special applications like corners, each
anchoring unit should match up with one facing unit.
• Drain pipe is required for walls over 4 ft. (1.2 m) tall or are constructed in
• Fill the hollow cores and a minimum of 12 in.
•
•
•
(300 mm) behind the wall with wall rock.
Install the wall rock to be level or below the
receiving notch of the anchoring unit.
Use approved soils to backfill behind the
wall rock and in front of the base course.
Use a plate compactor to consolidate the
area behind the blocks.
Compact in lifts of 8 in. (200 mm) or less.
Install
anchoring
units
Install AB Fieldstone anchoring units.
Compact
parallel to
wall
Wall
rock
Fill void in front
of block
Install and compact wall rock and
backfill soils.
AB Fieldstone Anchoring Units
AB Fieldstone is a multi-piece retaining wall system where each block
assembly consists of a facing unit and an anchoring unit. These universal
anchoring units, short anchoring unit (SAU) and long anchoring unit (LAU),
are made of recycled materials and are used with the 812 and 824 facing
units. The long anchoring unit is an option for job sites that require taller walls,
but do not have room for excavation and geogrid placement.
• The maximum gravity wall heights using short anchoring units, with either
of the two facing units, is up to 5 ft. 8 in. (1.7 m) in good soil conditions.
• The maximum gravity wall heights using long anchoring units, with either
of the two facing units, is up to 9 ft. 8 in. (3.0 m) in good soil conditions.
Good soils conditions are defined as well-graded compactible granular
aggregate, with an internal angle of friction of 36° or greater.
You should always consult a registered professional engineer to determine actual site specific requirements or to account for seismic loading.
See page 13 for the complete Maximum Gravity Wall Height Chart.
45
Install AB Fieldstone
facing units. Level and adjust.
allanblock.com
812 facing units
with short
anchoring unit
(SAU)
824 facing unit
with short
anchoring unit
(SAU)
Long anchoring
unit (LAU)
Use with 812 or 824
facing units
AB Fieldstone Gravity Wall Construction
• Remove all excess material from the top surface of the AB Fieldstone
allanblock.com
Sweep to remove excess materials for
proper placement of next course.
From the second
course and above,
compact parallel
to wall starting on
blocks
Compact wall rock and backfill soils
starting on the blocks.
Install string line along 45°
chamfers for proper cap
placement
BUILD AB FIELDSTONE
units. This should include running a brush or broom across the receiving
notch to remove any debris.
• For faster installation and alignment of the second course, install the first
AB Fieldstone facing unit and AB Fieldstone anchoring unit at the same
time. Make adjustments so that the vertical seams are offset from the
blocks below by at least 3 in. (75 mm) or ¼ the length of block.
• Install the rest of the AB Fieldstone facing units using the first block as a
placement guide.
• Place AB Fieldstone anchoring units into the receiving slots of facing
units. Slide the two-piece assembly so that the lip of the anchoring
unit is placed into the receiving notch of the block on the course
below. Each anchoring unit should match up with one facing unit.
• Check and adjust for level and alignment of the AB Fieldstone facing units.
• Fill the hollow cores and a minimum of 12 in. (300 mm) behind the wall
with wall rock. Install the wall rock behind the anchoring unit to be
level or below the receiving notch or approximately 0.5 in. (12 mm)
below the top of the anchoring unit.
• Use approved soils to backfill behind the wall rock.
• From course 2 and above use a plate compactor to compact directly
on the blocks as well as the area behind the blocks. Compact in lifts of
8 in. (200 mm) or less.
• Remove excess material from the top surface and repeat steps to complete the wall to the height required. See page 55 for information on
ending walls with turn-ins.
Finishing an AB Fieldstone Wall
Filter Fabric Above Top Block/ Below Cap
Filter fabric is used on top of the top course of blocks and below the caps
to cover the back of the anchoring units. This will allow plantable soil to
be placed flush against the cap unit.
• Place a strip of filter fabric along the top of the anchoring units on the
top course of wall. Position so that the fabric starts at the back of the
facing unit and goes over the anchoring unit and down along the back
of the anchoring unit.
• Be sure to leave the top surface of the facing unit exposed so that the
cap sealant can be placed on the facing unit.
• Finish the wall with AB Capstones. Place first capstone on the wall to include a 1.5 - 2 in. (40 - 50 mm) overhang.
• Run a string line the length of wall to mark placement of additional
capstones. To get a consistent point, use the 45 degree chamfers at
the end of each cap as alignment points for string line.
• Use a flexible masonry adhesive, NP1 or equivalent, to secure the capstones in place. Put a small bead of sealant along the sides of the caps
as well.
Install filter fabric and
string line to place AB Caps.
Cap block
45° chamfer
String
line
Install cap with an
overhang to achieve
a nice shadow line
• Backfill behind the last course and behind the AB Capstone with impermeable fill to allow for planting up to the back of the wall.
Note: To help hold the filter fabric in place while backfilling, place a spot
of sealant between the fabric and the anchoring unit.
allanblock.com
46
AB Fieldstone - Reinforced Wall Construction
See page 26 for complete details on proper steps for site prep,
drainage requirements and installing the base material for a reinforced wall. Projects must be built to the approved plans and specifications provided by a local engineer.
Install
facing
units
• Begin at the lowest wall elevation by placing the AB Fieldstone facing units
on the base material towards the front of the trench, leaving room for the
AB Fieldstone anchoring unit so when entire assembly is installed it is
centered on the base materials. Install a string line at the back of the
facing unit to ensure the proper positioning of all facing units.
• Adjust for level and alignment as each facing unit is installed.
• For proper placement of the AB Fieldstone anchoring units, use a brick
hammer to create a small trench to allow for the lip.
• Install the AB Fieldstone anchoring units into the receiving slots of the
facing units with the lip facing down in the trench just created. Make
adjustments to ensure anchoring units are installed reasonably level with
the facing unit. The anchoring units should never be installed higher
than the facing unit. Except for special applications like corners, each
anchoring unit should match up with one facing unit.
• Drain pipe is required for walls over 4 ft. (1.2 m) tall or are constructed in
Install AB Fieldstone
facing units. Level and adjust.
Install
anchoring
units
Install AB Fieldstone anchoring units.
• Fill the hollow cores of the base course and a minimum of 12 in. (300
•
mm) behind the wall with wall rock. Install the wall rock to be level or
below the receiving notch of the anchoring unit, see page 45. A
compactible aggregate ranging in size from 0.25 in. to 1.5 in. (6 mm to
38 mm) in diameter, and containing less than 10% fines is
recommended.
Use approved soils to backfill behind the wall rock and in front of the
base course.
Step 3: Compact
Compaction of the material behind the block is critical for a quality wall.
• Use a mechanical plate compactor to consolidate the wall rock, then
compact the backfill material immediately behind the block. Compact
in a path parallel to the wall, working from the back of the block to the
back of the backfill material See page 33 for additional details on
compaction.
• Check the base course for level and adjust as necessary.
• All backfill soils must be compacted to a minimum 95% Standard
Proctor. Use equipment appropriate for the soil being compacted.
• Remove all excess material from the top surface of all AB units. This
prepares a smooth surface for placement of the next course. This can
be assisted when installing the next course of block, by sliding the
block into place.
• Every course after the first course requires compaction starting on the block.
47
allanblock.com
Compact
parallel to
wall
Install wall rock. Compact wall rock
and backfill soils.
Infill
soils
Wall
rock
Fill void in front
of block
Sweep to remove excess materials for
placement of geogrid.
AB Fieldstone - Reinforced Wall Construction
Step: 4 Install Geogrid
• Cut sections of geogrid to specified lengths. Check manufacturer’s
grid specifications for strength, and roll or machine direction. Refer to
• After the base course of blocks has been installed, roll out the geogrid
reinforcement starting in the middle of the AB Fieldstone facing unit and
extending back to the excavated area. The excavated area must be
fully compacted and level.
• Stack the next course of block (facing and anchoring units) on top of
the geogrid so the blocks are offset from the blocks below. Each new
course should be positioned so the vertical seams are offset by at least
3 in. (75 mm) or 1/4 the length of the block. Perfect running bond is
not required. The facing units can be randomly flipped upside down to
give different facing appearances.
• Sight down the wall line to check for a straight wall. Blocks may be
adjusted slightly to form straight lines or smooth flowing curves.
• Pull on the back of the geogrid to remove any slack. Stake in place
before installing wall rock and approved infill soils.
Step 5: Backfill and Compact
• Install wall rock in block cores and 12 in. (300 mm) behind wall. Use
•
•
•
Install geogrid
per approved
plans
Install geogrid. Start in the middle of
the facing unit and extend behind wall.
Pull back geogrid
and stake in
place
Set next
course on top
of geogrid
Stake geogrid in place. Install next
course of block.
Compact
in 8 in.
(200 mm)
lifts
Compact
parallel to
wall starting
on blocks
From the second course and up, compact starting on the wall and working
to the back of the reinforced zone.
• Repeat steps 3 & 4 to complete wall to height required, installing
•
•
geogrid where needed per the approved plans.
Use 8 in. (200 mm) of impermeable fill on the last lift to finish off wall.
See page 46 for information on capping and page 55 for information
on ending walls with turn-ins.
allanblock.com
48
BUILD AB FIELDSTONE
•
•
approved infill soils to backfill behind the wall rock in the reinforced zone.
All wall rock and infill soils within 3 ft. (0.9 m) of the wall must be
properly compacted using a mechanical plate compactor. Compact
in maximum 8 inch lifts (200 mm), this time starting on the block and
working in a path that runs parallel to the block towards the back of
the reinforced zone. Compact all materials to a minimum 95%
Standard Proctor.
Never operate compaction equipment directly on geogrid.
All heavy equipment must be kept at least 3 feet (0.9 m) from the back of
the wall. Wall designs typically do not account for surcharges from heavy
compaction equipment. Even a properly installed and compacted wall
will rotate forward when extreme surcharges from heavy equipment are
applied to the top of the wall during construction and final grading.
build up of tolerances or an out of level base condition. Asphalt shingles or
geogrid work well when shims are required. The maximum allowable shim
thickness per course is 1/8 in. (3 mm).
Remove all excess wall rock and ridges or slag material from the top
surface of all AB units. This prepares a smooth surface for placement of
the next course. Plate compactors operated on top of the block will
remove most slag material and prep the block for the next course.
When installing the next course of block, sliding the block into place will
also remove any slag material.
allanblock.com
Inside and Outside Curves with AB Fieldstone
Building curved and serpentine walls are simple. AB’s patented design
allows for easy installation of both inside and outside curves. For walls
requiring geogrid, see page 58.
• Try to maintain an offset of the vertical seams by at least 1/4 of the
block length from the courses below for both inside and outside curves.
Inside Curves
• Place the facing units to form a flowing curve.
• Set anchoring units in place with the back of anchoring units fanned
out to form the curve.
Outside Curves
• Place the facing units to form a flowing curve.
• Remove one or both of the wings from the anchoring units to achieve
an outside curve. Then set the anchoring units in place.
• See the radius chart to determine the minimum radius for the base
course of an outside curve.
Remove wings
for outside
curves
Outside
Curve
Consistent
spacing
Inside
Curve
Keep the front
of the block
tight together.
Table 5.1
AB Radius Chart for the
Base Course of AB Fieldstone
812 facing unit
w/SAU (short
anchoring unit)
6° (Ref)
Wall Height
4 ft
1.2 m
6 ft 7 in.
2.0 m
6 ft
1.8 m
7.0 ft
2.1 m
8 ft
2.4 m
7 ft 5 in.
2.3 m
7 ft 10 in.
2.4 m
The 824 units are to be used in straight walls or gradual
curves only. In tight curve transitions, use 812 units only. Use
this chart to find the minimum recommended radius at
base of wall. Note all lengths, dimensions and setbacks are
approximate.
Remove wings
Modifying Anchoring Units
• Removing the “wings” of the blocks will be needed on projects with
curves, corners or step downs. For smooth outside curves, remove one
or both of the “wings” from the back of the anchoring units and tighten
the radius of the curve. Break wings off with a hammer and chisel in the
existing score line to obtain a clean break.
• When working with corners and/or stepping down a wall, split an anchoring unit in half to tie the corner together. Split the block by using a
hammer and chisel to make a break down the center of the block.
• On some projects you will need to modify the bottom lip of the block to
fit on the course below. Use a hammer and chisel and tap along the lip
to remove.
49
10 ft
3.0 m
allanblock.com
Split anchoring
unit in half
Remove
bottom lip
Inside and Outside Corners with AB Fieldstone
Outside Corners - Some of the AB Fieldstone facing units are manufactured with a textured side that compliments the facing unit. Besides
being used as a standard block, these blocks can be used to create a
corner. To create a left or right hand corner simply flip the facing unit as
needed to change the direction. For walls requiring geogrid, see page 60.
• Whenever possible, begin your wall at the corner. Install a facing unit
with the textured end facing out at the corner. Install an additional facing unit perpendicular to create a corner. Install additional facing units
in both directions to continue down the wall. Check for level. (Step 1)
• Starting at the corner and working out in both directions, use anchoring
units to span the first two facing units in each direction. (Step 2) Both of
these anchoring units will need to be modified slightly. On the base
course and above remove the wing from one anchoring unit. From
course two and above, remove part of the lip off the other anchoring
unit so that it fits on top of the course below. (Step 3)
• Use half of an anchoring unit on either side of the spanning anchoring units
to get pattern back to each facing unit having its own anchoring unit.
(Step 4)
• Align the lip and notch of the anchoring units in each direction to ensure proper placement of next wall course.
• Cut caps at 45 degree angles to complete the outside corner and give
the wall a custom finished look.
Step 1
Step 2
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1st Course
Half anchoring units
Remove wing
from full
anchoring
unit
Step 3
2nd Course
Remove
wing
Half anchoring units
2nd Course
Inside Corner
Inside Corners - By alternating the block’s placement on each course of
the wall, an inside corner can be installed. The 824 facing units are ideal
for this task, but 812 facing units are acceptable. For walls requiring geogrid, see page 60.
• To create a 90° inside corner, begin by placing an AB Fieldstone facing
unit (A) at the corner. Then lay a second facing unit (B) perpendicular
to the first. This second unit (B) must extend past the back of the first
facing unit (A). Continue laying out the rest of the base course working
from the corner out in both directions. Install the anchoring units.
• On additional courses alternate the placement of the facing units. Remove the lip from the anchoring unit, where the anchoring unit sits on
the facing unit below as needed.
• Cut caps at 45 degree angles to complete the inside corner and give
the wall a custom finished look.
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Anchoring
unit
Extends past
back of block
A’s anchoring
unit
B
Extends past
back of block
A’s anchoring
unit
A
B
A
Anchoring
unit
50
BUILD AB FIELDSTONE
Remove
lip
Step 4
Outside Corner
1st Course
Step Ups and Step Downs with AB Fieldstone
Step Downs - Creating a Step Down is similar to building an outside corner
as it uses the same facing units that are manufactured with a textured
side and has the same placement of the anchoring units.
• Install the facing units up to the Step Down location. Install the facing
unit with the textured end perpendicular to create a corner, with the textured face placed to face out.
• Split an anchoring unit in half. Take one half and remove the bottom lip
and place in the facing unit that was used to create the Step Down.
See page 49 for details on modifying an anchoring unit.
• The next anchoring unit will be installed in the first two facing unit’s that
lead up to the Step Down. This anchoring unit will span two facing units.
One of the wings of this unit will need to be removed to allow placement.
• Use the other half of the previous anchoring unit in the next slot to get
pattern back so each facing unit has its own anchoring unit.
• Use a flexible masonry adhesive to secure the corner units in place.
Remove
bottom lip of
anchoring
unit
Modify half an anchoring unit by
removing lip to secure the facing unit
Full anchoring
unit, spanning
blocks to secure
Step-Down
Half anchoring
units
Remove wing
from anchoring
unit
Install the half of an anchoring unit.
Step Ups - When building Step-Ups into a slope, always begin at the lowest
wall elevation of the base course. For more information see page 27.
• To create a Step-Up, span a block between the leveling pad and the
block course below. Step-Ups are most stable when the upper block
has sufficient bearing on the lower block. The length of the 824 assembly (if available) provides the flexibility to make this block ideal for this
application. An 812 assembly will work as well.
Use a block to
span for Step-Ups
(824 unit works
best).
Create the Step-Up using an 824 unit if
available.
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allanblock.com
Parapets
Parapets can be built on an existing surface or to finish off the top of a
retaining wall. It is now easy to incorporate patio enclosures, fencing or
planters with the same product for the entire project.
When building parapets the AB Dogbone unit will be
needed along with wall rock to fill the center void between the facing units to provide additional mass and
pullout resistance. AB Dogbone units are half the height of
the facing units. Two units are needed per 812 facing unit.
AB Dogbone unit
Parapet filled
with wall rock
allanblock.com
Long anchoring
unit (LAU)
AB retaining
wall below
Parapet Widths
AB Dogbone unit is
connected to both
facing units
Determining the width of the parapet will depend on what function it will
perform, but there are two options.
Option A: Standard Parapet - (Opposing facing units attached to
each other with the AB Dogbone unit) The AB Fieldstone parapets can be
built with a standard width by installing the AB Dogbone units attached to
both facing units. This standard width works well for straight walls and to
build corners, but cannot accommodate curves. Typically, you will end the
standard parapet with a post.
Corner
facing unit
Cut a facing
unit to create
the corner
Standard Dogbone Interlocked Parapets with Corners
Facing unit
extends in to
create corner
• Install the facing units up to the corner. Place the corner facing unit to
create the outside corner.
• The facing unit on the inside will need to be cut to allow for the
opposite facing unit to extend in to create the corner.
• Install AB Dogbones and wall rock. AB Dogbone units need to be installed in a staggered placement with the facing unit, one upper, one
lower. Place the lower AB Dogbone units (one per facing unit). Backfill
the wall rock in 4 in. (100 mm) lifts to allow for staggered placement of
the AB Dogbone units. Place upper AB Dogbone units in the opposite
side of the facing unit, finish backfilling with wall rock. Two AB Dogbones
are needed per facing unit and should have this staggered placement.
Posts and Standard Dogbone Interlocked Parapets with Posts
Stand alone posts are built using four corner facing units per course.
These blocks have a textured side as well as a textured face. Larger
posts can be built by adding cut or full length 812 units to each face.
• For Posts, every facing unit needs to have one AB Dogbone unit to
secure in place. Fill posts with wall rock in 4 in. (100 mm) lifts to allow
for staggered placement of AB Dogbone units.
• For Parapets with Posts. Finish a standard width parapet to post location
installing AB Dogbones that connect to both facing units. Install a post
at end of parapet panel.
• When building Posts within the wall, the corner facing units do not need
to be used where the wall meets the post as the textured side is not visible. Use four corner facing units for each course that exceeds the
height of the adjoining parapets.
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BUILD AB FIELDSTONE
When building corners, a facing unit will need to be cut for each
course to create the corner.
Corner
facing units
Posts
Corner facing
units
Parapets With Posts
Posts within Parapets
Corner
facing
units
812 facing
units
812 facing
unit
52
Option B: Wider Parapets or Curved Parapets – This option accommodates any width since the AB Dogbone Units are not connecting the facing units. There are a few widths that make construction easier. A slightly
wider parapet that requires no cutting uses two corner blocks to end the
wall and works extremely well in straight, corner and curved applications.
Straight Parapets - No Cutting Needed
• Begin by placing the AB Fieldstone facing units on the base material or existing surface. Check for level and alignment.
• Install AB Dogbones and wall rock. Stagger the AB Dogbone units, one
up and one down with the facing units to ensure each facing unit has
two AB Dogbones securing it in place for every course. Install lower AB
Dogbone units first, then backfill with wall rock in 4 in. (100 mm) lifts.
Place upper AB Dogbone units, finish backfilling with wall rock.
• Use care when backfilling with wall rock so facing units do not move out
of alignment. External jigs or supports may be required.
Corner
facing
unit
AB Dogbone units do not
connect to facing unit
behind on wider parapets
Wider Parapets - Ending and Corners
To create a wider parapet end with minimal cutting, we recommend using two 812 corner facing units (A) on odd courses
and one cut 824 facing unit (B) on the even courses. However, you can create your own parapet width because the
AB Fieldstone parapet can be built with custom spacing between to create a wider planter or bar as examples.
Curved Parapets
A
A
B
A
A
Cut a block to
create corner
Block extends in
to create corner
• When building curved parapets, the parapet must be wider than the
standard parapet application because the AB Dogbone units do not
line up or attach to both facing units.
• To ensure equal spacing between the facing units remain correct and
parallel to each other, level and plumb each course using a tape measure, jig or clamp.
• Stagger the AB Dogbone units, one up and one down with the facing
units to ensure each facing unit has two AB Dogbones securing it in place
for every course.
AB Dogbone units do not connect
to facing unit behind
All parapet graphics are to show AB Dogbone placement. All parapet installations
need to include wall rock in cores.
Using Multiple Series Faces
What is unique about AB Fieldstone? You can choose from different
facing options to match or compliment your natural surroundings.
Every facing unit is created to emulate the look and feel of natural
stone. By then blending the series faces together you can create your
own perfect look and style.
53
allanblock.com
Colonial and Sierra
faces blended together.
CONSTRUCTION DETAILS
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Expanded details on building with Allan Block.
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55
56
58
59
60
61
63
65
67
69
72
Finishing Walls
Curves
Curves with Geogrid
Corners
Corners with Geogrid
Stairs
Terraces
Design Details
Material Estimate Worksheet
Geogrid and No-Fines Estimating Charts
54
Finishing Walls
Ending and Topping Off Walls
Allan Block offers a great variety of finishing options for the wall.
Mulches: Allan Block’s patented raised front lip provides a built-in edging
for landscape rock, mulch, grass or soil.
AB Capstones: AB Capstones can be used to finish off the top of a wall.
Use a high grade, waterproof flexible masonry adhesive to secure
AB Capstones in place.
See allanblock.com for information on cutting AB Capstones for curves or
corners.
Mulch or Soil
Building Step Downs
Walls with step downs can be easily finished by adding a AB Lite Stone, or
turning the ends back into the hillside. For tips with patterned wall Step
Downs, see page 40.
Our recommendation for a gradual step-down is using the AB Lite Stone.
AB Capstones
For a full course step-up, use the AB Corner Block.
Excavate, backfill
and compact for
turn-in
Building Turn-Ins
For a graceful, flowing end
to the wall, curve the wall
to create a plantable area
that can soften the look of
the wall.
When building a turn-in, a
base trench will need to be
excavated, backfilled and
compacted, the same as
the base course of blocks.
Building Turn-Ins
Install blocks
and compact
turn-in
55
AB Capstones with step ups
Proper backfilling and
compaction is important,
where the wall turns back
into the slope. To ensure the
turn-in area doesn’t settle
differently than the rest of
the wall, make sure the entire
area below the new base is
compacted thoroughly.
allanblock.com
Flowing turn-in of wall
For a step-down that doubles as a planter, turn the
wall in 2 or 3 blocks after the AB Corner Block.
For a natural flow into the landscape, curve
the wall back into the hillside.
Construction Details - Curves
Building curved and serpentine walls is simple. AB's patented design allows for easy installation of both inside and outside curves.
Most curves can be built with no cutting involved.
allanblock.com
• Try to maintain an offset of the vertical seams by at least ¼ of
the block length from the courses below. Cutting a block in
half or using the half width blocks, will assist in creating a
proper offset.
• Before beginning construction, review the plans
and layout the wall to eliminate tight radii. More gentle
sweeping curves produce more aesthetically pleasing walls.
See page 57 for the radius chart.
• Use blocks with lower setbacks or half width blocks on curves
for smoother transitions.
Remove wings
for outside
curves
Consistent
spacing
Inside Curves
• To build a flowing inside curve, butt the block end to
end to match the smooth curve required on the
project. Try to keep spacing consistent between the
backs of the blocks.
Outside Curves
• To build smooth outside curves, remove one or both of the
"wings" from the back of the blocks and tighten the radius of
the curve. Break wings off by tapping on the back of the wing
to obtain a clean break.
Outside
Curve
Inside
Curve
Keep the
front of the
block tight
together.
Cutting The Bottom Notch
For Tighter Inside Curves
the courses. For cleaner lines, it may be necessary to remove
parts of the bottom notch to fit the blocks closer together.
Area of notch
to remove on
bottom of block
Tighter Curves
• Using full size blocks in tight curves will create a gap between
Cutting The Bottom Notch For
Tighter Outside Curves
Area of notch to
remove on bottom
of block
allanblock.com
56
Working with Radii
• Refer to Table 6.1 to confirm that the AB product you are using
will accommodate the desired wall radius.
• The tightest or smallest radius at the top of any AB wall using full
size block is 4 ft. (1.2 m), and 2.5 ft. (0.8 m) using the half width
blocks. The final height of the wall will determine what the
minimum radius at the base course must be. The wall creates a
coning effect as it is stacked up, creating the need for a larger
radius at the base course. Use the Radius Chart to determine
what the radius of the base course of the wall needs to be, so
the top course of the wall will not be less than 4 ft. (1.2 m).
Base Course Radius for an outside
curve on a 4 ft tall 6° wall
Center
Stake
Top course radius
4.0 ft (1.2 m)
Starting a Radius
From the point of where the curve will start, measure straight
back from the wall the required amount (shown in the Radius
Chart) and drive a stake into the ground. This will be the center
of the curve. Attach a string line to the stake the length of the
radius and rotate it around to mark the location of the base
course. Install the blocks with the front of the blocks lining up with
the mark.
Base course radius
5 ft 2 in. (1.6 m)
Setback
AB Radius Chart for
the Base Course
AB & AB Europa
Collection
Full Size Blocks
3° (Ref)
• To transition the curve back into a straight wall or another
curve, lay out the curve and the first couple blocks of the next
section. Adjusting 1 or 2 of the blocks will help in the transition
of the next section of wall.
6° (Ref)
12° (Ref)
AB Fieldstone
Collection
812 facing unit
w/short anchoring
unit (SAU)
6° (Ref)
AB & AB Europa
Collection
Half Size Blocks
6° (Ref)
Wall Height
Table 6.1
4 ft
6 ft
8 ft
10 ft
4 ft. 9 in.
1.43 m
5.0 ft
1.52 m
5 ft. 4 in.
1.6 m
5 ft. 8 in.
1.7 m
5 ft. 6 in.
1.7 m
6.0 ft
1.8 m
6 ft. 6 in.
2.0 m
7.0 ft
2.1 m
1.2 m
5 ft. 2 in.
1.6 m
4 ft
1.2 m
1.8 m
5 ft. 6 in.
1.7 m
6 ft
1.8 m
2.4 m
5 ft. 11 in.
1.8 m
8 ft
2.4 m
6 ft. 7 in.
2.0 m
7.0 ft
2.1 m
7 ft. 5 in.
2.3 m
0.6 m
1.2 m
1.8 m
2 ft
3.0 ft
0.9 m
4 ft
3 ft. 5 in.
1.0 m
6 ft
3 ft. 10 in.
1.15 m
3.0 m
6 ft. 4 in.
1.9 m
10 ft
3.0 m
7 ft. 10 in.
2.4 m
Use this chart to find the minimum recommended
radius at base of wall. Note all lengths, dimensions
and setbacks are approximate.
For a smooth curve with less cutting, use our half width blocks to
help build the curve.
57
allanblock.com
Construction Details - Curves with Geogrid
Inside Curves
Geogrid needs to have 100% coverage around an inside curve.
To achieve this, additional layers need to be installed either
above or below the course where the grid is required to fill voids
that are created.
allanblock.com
• Cut geogrid to required lengths per the approved plan.
• Lay out the primary geogrid around the curve butting front edges
together. Make sure strength direction runs perpendicular to wall
face. Mark the blocks or take note of the areas where there
are voids in the grid placement.
• Place the filler piece of grid on the next course (or the course
below) to cover the void left on the primary layer.
Additional grid layer placed
on next course to eliminate
gaps from course below
Top View
Mark
blocks
Trim grid
to fit curve
Primary layer
Outside Curves
• Cut geogrid to required lengths per the approved plans.
• Lay out the geogrid around the curve.
• Lift the section of grid that overlaps and place the fill material
to separate. Grid layers need to be separated by a 3 in.
(75 mm) layer of approved fill material.
• Never compact directly on the geogrid.
Grid layers need to be separated by a 3 in.
(75 mm) layer of approved fill. Lift the area
of grid up and place in the fill material to
separate the layers
Place soil
between
the layers
Trim grid
to fit curve
Top View
allanblock.com
58
Construction Details - Corners
Inside Corners
AB Blocks are easily modified to build inside corners. To construct an
inside corner, you will remove part of the raised lip on one block on
each course.
Step 1
Step 2
• Use a saw with a diamond blade or a chisel to remove half of
the raised front lip. This allows the next course to be installed on
a level surface (Step 1).
• Lay the modified block perpendicular to another AB unit. This
creates the corner (Step 1).
• On the next course, remove the opposite half of the lip of an
AB unit and position it over the right angle corner (Step 2).
• On each successive course, simply reverse the
position of the modified block to obtain an
interlocked corner.
Remove part of
front lip so next
course will seat
properly
Remove notch to
form corner
Area of
front lip
removed
Outside Corners
AB Corner Blocks are used to build outside 90° corners.
To construct an outside corner, you will use an AB Corner Block on every
course, alternating a right and left hand corner for each course. Additional corner construction information can be found at
allanblock.com.
• Start construction of all walls
Blocks with
part of lip
removed
3 in. (75 mm)
minimum overlap
at the corner. This will keep
the block alignment within
the 3 in. (75 mm) overlap
required.
• Place an AB Corner Block at
the corner. Place AB Blocks
to build the base course
working out from the corner
in both directions (Step 1). Level, backfill and compact.
• On the 2nd course place an alternating AB Corner Block. Again work
out from the corner in both directions. Level, backfill and compact
(Step 2).
• Repeat this procedure, alternating every other course with AB Corner
Blocks. Leveling, backfilling, and compacting as the wall grows (Step 3).
Step 1
Step 2
Altering AB Corner Blocks for Different Setbacks
AB Corner Blocks are manufactured with a 12° setback. With some minor
adjustments, the blocks can be modified to work with any setback. To
modify the block for a 6° setback, cut a notch on the short side of the
block 0.75 in. (20 mm) deep.
For a 6° setback, make
a horizontal cut 0.75 in.
(20 mm) deep
Remove this
piece after
cut is made
59
allanblock.com
Step 3
Ensure base is
level going both
directions
Construction Details - Corners with Geogrid
Installing Geogrid on Inside 90° Corners
On inside corners additional geogrid is required to extend past
the end of the wall, 25% of the completed wall height (H/4).
Geogrid with Inside 90° Corners
Location of 1st
required layer of
geogrid
• Cut geogrid to required lengths per the approved plan.
As a general rule the length of the geogrid needs to extend
a minimum of 25% of the wall height past the end of the
inside corner.
• Install the layer of geogrid with the geogrid extending past
the inside corner.
Geogrid must always be installed with its strong direction
perpendicular to the face of the wall. To accomplish this with
90° outside corners:
allanblock.com
The length of geogrid
that extends past the
wall, 25% of the entire
wall height (H/4)
• Alternate the next layer of geogrid to extend the past the
inside corner in the opposite direction.
EXAMPLE:
Finished wall height is 12 ft. (3.7 m), divide by 4 which equals
3 ft. (0.9 m).
The length the grid will need to extend past the corner
is 3 ft. (0.9 m).
e or
chin ion
Mall direct
ro
Location of 2nd required
layer of geogrid
M
roll ach
dir ine
ect or
ion
Geogrid with Outside 90° Corners
Installing Geogrid on Outside 90° Corners
Location and direction
of 1st required layer
of geogrid
• Cut geogrid to required lengths per the approved plans.
M
rol ach
l di ine
rec or
tion
• Install geogrid to the outside corner with the roll direction
running back into the excavated site.
e or
chirnection
a
M l l di
ro
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• On the next course of block, lay the next layer of grid
perpendicular to the previous layer.
Location and direction
of 2nd required layer
of geogrid
60
Construction Details - Stairs
Basic Stair Construction
Always check local code requirements before building any type of stair
application. The steps below are general guidelines for building stairways.
By understanding the basic installation elements, stairways can be easily
incorporated into the wall installation.
• Before excavation can begin, the rise and run of the stair treads must
be determined and code requirements must be met. With that information, the entire base trench can then be excavated. Some examples of different stair tread options are illustrated below.
Our example here uses a base trench of 6 in. (150 mm) and a stair tread
of AB Capstones and pavers.
Excavate for stairs
and compact.
Install and level blocks on
base material.
• Excavate to the necessary depth and width for each stair riser and
thoroughly compact the entire area to 95% Standard Proctor with
a mechanical plate compactor.
• Check for level.
• Starting at the first step, fill the base trench with 6 in. (150 mm) of
wall rock. Rake smooth.
• Compact and check for level. Stairs need extra compaction to avoid
any settling later. Better compaction is achieved by backfilling and
compacting in 4 in. lifts (100 mm) or less when able.
Backfill block cores and
behind block with wall
rock. Compact.
• Install blocks on the base material. Allow for a space of at least
6 in. (150 mm) behind the blocks for wall rock.
• Adjust for level and alignment of each block as it’s installed.
• Install wall rock in the block cores, fill any space in front of and
behind the block. When backfilling behind the blocks, fill the entire
area that was earlier excavated to create the base for the next stair
riser. This should produce a level base for the next set of risers. We recommend backfilling and compacting behind the block in
4 in. lifts (100 mm) to achieve better compaction when able.
• Rake wall rock smooth and compact with the first pass of the compactor directly on the tops of the block and then working in a path that
runs parallel to the block. Compact to 95% Standard Proctor.
• Repeat this process for each additional course of steps needed.
Install next
stair course.
Continue for each new stair.
Stair Tread Options
AB Capstones
61
AB Capstone
and Pavers
Pavers
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Concrete
Stairs can be designed with flowing curves or straight lines. Curved
sidewalls create a softer, natural look. Straight sidewalls and corners
offer a crisp, traditional style; however they require AB Corner
Blocks and take more time to build.
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Allan Block’s patented front lip provides a built-in edging that works
well when installing the stair tread material. Allan Block Capstones,
pavers, poured concrete, crushed rock, mulches and flagstone are
good stair tread examples. Ensure that stair treads are secured in
place for safe use.
Additional stair designs and technical information explaining the
construction process is available on our website at allanblock.com
or from your local Allan Block representative.
Remember to always check with the local codes before construction.
To find the number of steps needed, measure the
total rise of your slope in inches (mm) and divide
by 8 in. (200 mm) which is the height of a step.
Rise - 48 in. (1220 mm)
48 in. ÷ 8 in. = 6 steps
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62
How Many Steps?
Construction Details
Terraces
It is often more aesthetically pleasing to replace one large
retaining wall with two or more smaller terraced walls. Terraced
walls can act as surcharges and may create global instability,
therefore reinforcement may be necessary. Always check with
a local qualified engineer when building terraces.
Walls perform independently and may not need engineering
when the distance between gravity walls is at least two times the
height of the lower wall, and the height of the upper wall is equal
to or less than the height of the lower wall. Use the Gravity Wall
Chart on page 13 to determine if geogrid is required or check
with a local wall engineer.
Walls that must be evaluated by an engineer are any walls needing geogrid reinforcement, walls closer than two times the height
of the lower wall, walls with more than two terraces, and terraced
walls with any structures above.
Terraced walls that do not perform independently must also be
evaluated for global stability, and the lower walls must be designed to resist the load of the upper walls.
Terraces
63
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Water Applications
Retaining walls constructed in conditions where there is moving
water (streams), standing water with wave action (lakes), or retention ponds are considered water applications.
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Water applications must be evaluated and designed to fit the
unique characteristics of the site. Consult with a local qualified
engineer for design assistance.
Water Application
Fences/Guide-Rails
There are several options for installing fences and guide rails on
top of an Allan Block wall. The structure and wind loads of the
materials used will determine the placement of the fence relative
to the AB wall and if additional reinforcement is required. Refer to
the approved plans for construction details.
Lighting
Allan Block’s hollow core design makes it easy to install lighting.
Cut a hole in the location where the light will be to accommodate the wiring and attachment of the light to wall face.
Carefully follow the manufacturer’s instructions for lighting and
electrical installation, as various fixtures may be assembled
differently. Always check local building codes for electrical
installation requirements.
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64
Design Details
All drawings are for information only and not for construction. See the approved plans for exact details or contact the
local engineer of record for written guidance. See allanblock.com for additional details and information.
Typical Reinforced Wall Application
Typical Gravity Wall Application
Typical Water Application
Swales
Chimney Drain and Blanket Drain
Alternate Drain
65
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Wind Bearing Fence or Railing, Option 1
Wind Bearing Fence or Railing, Option 2
Non-Wind Bearing Fence or Railing
Double Wall Parapet
Impact Barrier
Non Impact Rail
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66
To ensure that the basics of the retaining wall project are
covered, use the following construction and inspection checklist.
For a thorough procedure use this list as a guide to prepare your
project specific checklist and to review the most common points.
It may also be used during the bidding process or a pre-construction meeting to ensure that all special provisions are complied with.
Always check the local building codes, document any changes
to the plan in writing, and notify the wall design engineer with any
concerns on water management.
Typical Reinforcement Cross Section
Review wall design plans for:
A. Compliance of site to latest site plan
• Does the site plan and wall layout coincide with current site conditions?
• Have all slopes above and below the walls been taken into account on the plans?
• Do the section drawings match the topography of the job-site?
• Have site utilities been accounted for?
• Are there any recommendations for changes to the site plans to accommodate the wall?
B. Review of reported soil conditions with on-site soils engineer
• Are on-site soils consistent with soil parameters used in wall design?
• Does the site show indications of multiple types of soil, and has this been accounted for?
• Is there evidence of landfill areas on site?
• Has the owner contracted with a geotechnical engineering firm for overall / global stability outside the wall design
envelope (H tall by the greater of 2H or He + L long)?
C. Review of above-grade water management with project civil engineer
• Has surface runoff been accounted for in the site design?
• Will this site be irrigated?
• If storm drains become inoperable where will the water migrate to?
• During renovation of land will temporary drainage be an issue?
67
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D. Review of below grade water management with wall design engineer
and general contractor
• How and where will drain pipe be installed?
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• Is it possible to vent drain pipe to daylight?
• Is venting to a storm drainage system an option?
• Will outlets be located and protected from blockage or damage?
E. Surcharges
• Have all surcharges been accounted for?
• During construction are there any temporary surcharges that should be accounted for?
Review Construction Details And Procedures:
A. Mark station points for top and bottom of wall elevation and change in wall direction.
B. Identify changes in grid lengths, location of grids, and types of grid to be used.
C. Determine and locate proper base size for each section of wall.
D. Verify that the correct type and color of block has been ordered and delivered to the job.
E. Verify that the foundation soil and retained soil conform to design requirements.
F. Verify that infill soil meets design standards.
G. Verify that compaction testing will be performed, who is responsible, at what
intervals of locations along the wall, and what coordination will be required.
H. Determine what method will be used to verify construction materials, methods, and sequence of
construction. (ie: written documentation of as built, full time inspector on site, photographic documentation.)
I. Wall contractor is responsible for quality control of wall installation per the approved plans. The owner or
owner’s representative is responsible for engineering and quality assurance of the project.
Additional Notes:
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68
Material Estimation Worksheet
Order Materials
Blocks: Ordering block is easy. Use the following steps or visit allanblock.com for helpful estimating tools.
Total LENGTH of wall(s)
WIDTH of the block
divided by
(÷)
ft. (m)
Total HEIGHT of wall(s)*
ft. (m)
HEIGHT of block
divided by
(÷)
ft. (m)
Blocks per course
equals
(=)
multiply (x)
Courses in wall
equals
(=)
ft. (m)
Notes:
* Wall height needs to have the amount of buried block included. Buried block should be
a minimum of 6 in. (150 mm) or 1 in. (25 mm) for each 1 ft. (0.3 m) of wall height. See the
approved plans to find out what the final height including the buried block will be.
**Extra blocks will need to be included if walls have step ups and/or stairs. Ordering an
extra 5% is always recommended to account for any problems during construction.
equals (=)
Blocks needed**
• See your local Allan Block dealer for exact block dimensions, which need to be used when estimating blocks.
Base and Consolidation Zone: Allan Block recommends using the same material for the base, within the block
cores and behind the blocks. A well-graded (balanced mix of grain sizes) compactible aggregate, 0.25 in. to 1.5 in.
(6 mm to 38 mm) diameter with less than 10% fines is needed. Check your local aggregate sources for availability.
These estimates use the minimum amount of material required to build a wall. See the approved plans for exact amounts.
A). Base: The minimum base for a geogrid reinforced retaining wall is:
Calculate:
2 ft. (0.6 m)
Width of base
x
0.5 ft (0.15 m)
Height of base
x
Length of wall
ft. (m)
2 ft. (0.6 m) wide x 0.5 ft (0.15 m) high.
=
Convert cubic feet (cubic meters) to tons by:
Wall Rock
ft3 (m3)
x
Wall Rock
ft3 (m3)
120 lbs/ft3 (1,923 kg/m3) ÷ 2000 lbs/ton (1000 kg/ton) =
Unit weight of rock
WALL ROCK IN TONS
B). Block Cores and Consolidation Zone: This includes the material in the block cores plus a 12 in. (300 mm) layer
behind the blocks.
Calculate:
Wall height
ft. (m)
x
Wall length
ft. (m)
x
1.4 ft. (0.43 m)
Convert cubic feet (cubic meters) to tons by:
Wall Rock
ft3 (m3) x
120 lbs/ft3 (1,923 kg/m3) ÷ 2000 lbs/ton (1000 kg/ton)
Unit weight of rock
C). Add the totals from A & B together:
69
=
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Wall Rock
=
ft3 (m3)
WALL ROCK IN TONS
Total WALL ROCK
Define Terms
Base Material - A base pad of granular material, compacted
and leveled to receive the base course of AB units.
Reinforced Zones - Area located directly behind the block that
runs to the end of the area being reinforced by any geogrid
reinforcement material.
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Consolidation Zones - The 3 ft. (0.9 m) area directly behind the
back of the block and extending toward the back of the
excavated area.
Compaction Zones - The area located behind the consolidation
zone that runs to the end of the area being disturbed by any
construction activities.
Geogrid - A manufactured high strength reinforcement grid
material that comes in rolls of various sizes and strengths.
Infill Soils - The soil used to backfill behind the wall rock in the
reinforced zone. These soils need to be identified and
approved by a qualified engineer before they can be used.
A granular type of material is best.
Drain Pipe - Used to direct incidental water that makes its way in
behind the reinforced mass, and vents it to daylight by creating a channel for the water to flow out from.
Wall Rock - Compactible aggregate ranging in size from 0.25 in to
1.5 in. (6 mm to 38 mm) with no more than 10% fines. Used for
base material, within block cores and behind the block.
Using the approved plan, contact your local geogrid supplier or Allan Block Representative for geogrid specifications and
assistance in ordering materials.
Geogrid
The length of the wall will usually determine the same amount of drain pipe needed. Check the approved plan for
exact specifications and locations of the drain pipe.
Drain Pipe
Using the approved plan, subtract 2 ft (0.6 m) from the grid length required. This figure will determine the depth for the
infill soils. (1 ft (0.3 m) for the block and 1 ft (0.3 m) for the wall rock behind the block)
Infill Soils
Depth area
ft. (m) x
ft. (m) x
Height of wall
AB Capstones
Wall length
ft. (m) x 120 lbs/ft3 (1,923 kg/m3) ÷ 2000 lbs/ton (1000 kg/ton) =
Length of wall
ft. (m) ÷
Unit weight of rock
ft. (m) =
Width of capstone
Infill soil
kg/ton
AB Capstones needed
Use one 29 ounce tube (820 gm) of adhesive for every 60 ft. (18 m) of wall length where capstones will be installed.
Adhesive for Capstones
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70
Geogrid and No-Fines Concrete Estimating Charts
These pre-engineered tables provide an accurate estimate for geogrid reinforcement and no-fines
concrete. To use the tables, follow these simple steps:
Case A
1) Verify that the site condition of your retaining wall matches the table being used.
2) Verify that the soil conditions at your site match the description given.
3) Choose the wall height needed for your site and read across to find the number of grid layers,
embedment length, grid locations or concrete depth.
4) Verify that excessive water runoff, or a high water table, is not present.
Design Parameters
Factors of Safety
Sliding
Overturning
No-Fines Overturning
Grid Pullout
Grid Rupture
=
=
=
=
=
Assumed Unit Weights
Earth Backfill
Filled weight of AB
Allan Block
No-Fines Concrete
1.5
2.0
1.5
1.5
1.5
=120 lbs/ft3 (19 kN/m3)
=131 lbs/ft3 (20.5 kN/m3)
=135 lbs/ft3 (21.1 kN/m3)
=110 lbs/ft3 (17.3 kN/m3)
Assumed Soil Capacities
Cohesion
Bearing Capacity 36° (Ref)
General
Proper drainage provided.
Grid meets ASTM D-4595.
Case B
Case C
1
= 0 psf (0 kPa)
4,000 psf (191.520 kPa)
3,500 psf (167.580 kPa)
2,500 psf (119.700kPa)
Grid
Long Term Allowable Design Strength (LTADS) 700 lbs/ft. (10,200 N/m)
Geogrid sections shown,
no-fines concrete similar
These charts should be used for estimating grid and no-fines concrete quantities for projects which match the site and soil
descriptions provided, and only for projects which use grid strengths of 700 lbs/ft. (10,200 N/m) or higher. No provision or
analysis for global stability or seismic activity are provided.
medium sands, clean
No-Fines Chart
Condition
Above Wall
Wall Height
ft
Case A
Level Slope
Above the Wall
Case B
100 psf Surcharge*
(4.7 kPa) Above the Wall
Case C
3H:1V Slope
Above the Wall
71
m
3
4
5
6
7
8
9
10
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
3
4
5
6
7
8
9
10
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
3
4
5
6
7
8
9
10
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
Buried
Block
in
cm
3
4
6
6
7
8
9
10
8
10
15
15
18
20
23
25
3
4
5
6
7
8
9
10
3
4
5
6
7
8
9
10
12° (Ref)
AB Stones only
of the
AB Collection
ft
m
ft
2
2.5
2.5
3
3.5
0.7
0.8
0.8
1
1.1
2
2.5
2.5
3
3.5
4
8
10
13
15
18
20
23
25
2
2.5
2.5
3
3.5
0.7
0.8
0.8
1
1.1
2
2
2.5
3
3
3.5
4
2
2
2.5
2.5
3
3.5
0.7
0.7
0.8
0.8
1
1.1
2
2
2.5
2.5
3
3
3.5
4
sands - f = 27°
Depth of No-Fines including wall facing
AB, AB Europa and
AB Fieldstone
Collections
(Excl. AB Stones)
8
10
13
15
18
20
23
25
Table 6.2
well graded sands,
6° or 3° (Ref)
m
12° (Ref)
AB Stones only
of the
AB Collection
ft
m
6° or 3° (Ref)
AB, AB Europa and
AB Fieldstone
Collections
(Excl. AB Stones)
ft
m
12° (Ref)
AB Stones only
of the
AB Collection
ft
m
0.7
0.8
0.8
1
1.1
1.3
2
2.5
2.5
3
3.5
0.7
0.8
0.8
1
1.1
2
2.5
2.5
3.5
3.5
4
0.7
0.8
0.8
1.1
1.1
1.3
2
2
2.5
2.5
3.5
3.5
4
0.7
0.7
0.8
0.8
1.1
1.1
1.3
0.7
0.7
0.8
1
1
1.1
1.3
2
2
2.5
2.5
3
3.5
0.7
0.7
0.8
0.8
1
1.1
2
2.5
3
3
3.5
4
4.5
0.7
0.8
1
1
1.1
1.3
1.4
2
2.5
3.4
4
4.5
5
5.5
6.5
0.7
0.8
1.1
1.3
1.4
1.6
1.7
2
0.7
0.7
0.8
0.8
1
1
1.1
1.3
2
2
2
2.5
2.5
3
3.5
allanblock.com
0.7
0.7
0.7
0.8
0.8
1
1.1
2
2
2.5
2.5
3
3.5
4
4
3
0.7
0.7
0.8
0.8
1
1.1
1.3
1.3
2
2
2.5
3
3.5
4
4.5
4.5
0.7
0.7
0.8
1
1.1
1.3
1.4
1.4
6° or 3° (Ref)
AB, AB Europa and
AB Fieldstone
Collections
(Excl. AB Stones)
ft
2
2.5
2.5
3
3.5
4
4.5
2.5
3
3.5
3.5
4
4.5
5
5
2.5
3
4
5
5.5
6.5
7
8
m
0.7
0.8
0.8
1
1.1
1.3
1.4
0.8
1
1.1
1.1
1.3
1.4
1.6
1.6
0.8
1
1.3
1.6
1.7
2
2.2
2.5
The charts below assume for geogrid reinforced walls, that the reinforcement starts
on the first course of block, and then every second course thereafter. The charts
below are for material estimates only, contact your local engineer for wall design.
Geogrid Chart
AB Stones - 12°
Condition
Above Wall
Case A
Level Slope
Above the Wall
Case B
100 psf Surcharge*
Top grid layer must
extend an extra
3 ft (0.9 m)
Case C
3H:1V Slope
Above the Wall
Wall Height
ft
3
4
5
6
7
8
9
10
m
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
3
4
5
6
7
8
9
10
3
4
5
6
7
8
9
10
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
Buried
Block
in
3
4
5
6
7
8
9
10
3
4
6
6
7
8
9
10
3
4
5
6
7
8
9
10
cm
8
10
13
15
18
20
23
25
8
10
15
15
18
20
23
25
8
10
13
15
18
20
23
25
Geogrid Chart
AB Classic - 6°, Patterned Walls - 6°,
AB Fieldstone - 6° & AB Vertical - 3°
Condition
Above Wall
Case B
100 psf Surcharge*
Top grid layer must
extend an extra
3 ft (0.9 m)
Case C
3H:1V Slope
Above the Wall
ft
3
4
5
6
7
8
9
10
3
4
5
6
7
8
9
10
3
4
5
6
7
8
9
10
m
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
Buried
Block
in
3
6
6
6
7
8
9
10
6
6
6
6
7
8
9
10
3
6
6
6
7
8
9
10
cm
8
15
15
15
18
20
23
25
15
15
15
15
18
20
23
25
8
15
15
15
18
20
23
25
# of
grid
layers
Grid
Lengths
ft
0
0
0
5
6
7
7
8
4
5
5.5
6
6.5
0
0
0
5
6
7
7
8
4
5
5.5
6
6.5
0
0
4
5
6
7
7
8
3.5
4
5
5.5
6
6.5
m
1.3
1.6
1.7
1.9
2
1.1
1.3
1.6
1.7
1.9
2
1.3
1.6
1.7
1.9
2
medium sands, clean
# of
grid
layers
0
3
4
5
6
7
7
8
2
3
4
5
6
7
7
8
0
3
4
5
6
7
7
8
Grid
Lengths
ft
3.5
4
5
5.5
6.5
7
7.5
3
3.5
4
5
5.5
6.5
7
7.5
3.5
4
5
5.5
6.5
7
7.5
m
1.1
1.3
1.6
1.7
2
2.2
2.3
1
1.1
1.3
1.6
1.7
2
2.2
2.3
1.1
1.3
1.6
1.7
2
2.2
2.3
well graded sands,
# of
grid
layers
Grid
Lengths
ft
0
0
0
5
6
7
7
8
4
5
5.5
6
6.5
0
0
0
5
6
7
7
8
4
5
5.5
6
6.5
0
0
4
5
6
7
7
8
3.5
4
5
5.5
6
6.5
m
1.3
1.6
1.7
1.9
2
1.1
1.3
1.6
1.7
1.9
2
1.3
1.6
1.7
1.9
2
well graded sands,
# of
grid
layers
0
3
4
5
6
7
7
8
2
3
4
5
6
7
7
8
0
3
4
5
6
7
7
9**
Grid
Lengths
ft
3.5
4
5
5.5
6.5
7
7.5
3
3.5
4
5
5.5
6.5
7
7.5
3.5
4
5
5.5
6.5
7
7.5
m
1.1
1.3
1.6
1.7
2
2.2
2.3
1
1.1
1.3
1.6
1.7
2
2.2
2.3
1.1
1.3
1.6
1.7
2
2.2
2.3
allanblock.com
sands - f = 27°
# of
grid
layers
0
3
4
5
6
7
7
8
2
3
4
5
6
7
7
8
2
3
4
5
6
7
7
9**
ft
Grid
Lengths
3
3.5
4
5
5.5
6
6.5
3
3
3.5
4
5
5.5
6
6.5
3
3
3.5
4
5
5.5
6
6.5
m
1
1.1
1.3
1.6
1.7
1.9
2
1
1
1.1
1.3
1.6
1.7
1.9
2
1
1
1.1
1.3
1.6
1.7
1.9
2
sands - f = 27°
# of
grid
layers
2
3
4
5
6
7
7
8
2
3
4
5
6
7
7
9**
2
3
4
5
6
8**
8**
10***
ft
Grid
Lengths
3
3.5
4
5
5.5
6.5
7
7.5
3
3.5
4
5
5.5
6.5
7
7.5
3
3.5
4
5
5.5
6.5
7.5
8.5
m
1
1.1
1.3
1.6
1.7
2
2.2
2.3
Case A
Level Slope
Above the Wall
Wall Height
medium sands, clean
Table 6.3
1
1.1
1.3
1.6
1.7
2
2.2
2.3
1
1.1
1.3
1.6
1.7
2
2.3
2.6
Note: All walls which require geogrid reinforcement shall have a minimum of 6 in. (150 mm) of buried block.
Tables 6.2 and 6.3 are based on Clay soil having an internal friction angle of 27° (Ref) or better and a Sandy soil having an internal friction angle of 32°
(Ref) or better and a Sand/Gravel soils having an internal friction angle of 36° (Ref) or better. All setbacks and dimensions are approximate. The wall
heights shown do not account for seismic loading. Check with a local engineer for assistance if you are in a seismic area. Final designs for construction purposes must be performed by a local registered Professional Engineer, using the actual conditions of the proposed site.
*The Surcharge loading category above assumes a solid surface such as concrete, asphalt or pavers having a suitable supporting subgrade.
** 1 course spacing for first 3 layers of grid. *** 1 course spacing for first 4 layers of grid.
allanblock.com
72
Specification Guidelines: Allan Block Modular Retaining Wall Systems
SECTION 1
PART 1: GENERAL
1.1 Scope
Work includes furnishing and installing modular concrete block retaining wall units to the lines and grades designated
on the construction drawings and as specified herein.
1.2 Applicable Sections of Related Work
Geogrid Wall Reinforcement (See Section 2)
1.3 Reference Standards
A. ASTM C1372 Standard Specification for Segmental Retaining Wall Units.
B. ASTM 1262 Evaluating the Freeze Thaw Durability of Manufactured CMU’s and Related Concrete Units
C. ASTM D698 Moisture Density Relationship for Soils, Standard Method
D. ASTM D422 Gradation of Soils
E. ASTM C140 Sample and Testing Concrete Masonry Units
1.4 Delivery, Storage, and Handling
A. Contractor shall check the materials upon delivery to assure proper material has been received.
B. Contractor shall prevent excessive mud, cementitious material, and like construction debris from coming in contact
with the materials.
C. Contractor shall protect the materials from damage. Damaged material shall not be incorporated in the project
(ASTM C1372).
1.5 Contractor Requirements
Contractors shall be trained and certified by local manufacturer or equivalent accredited organization.
A. Allan Block and NCMA have certification programs that are accredited. Identify when advanced certification levels
are appropriate based on complexity and criticality of project application.
B. Contractors shall provide a list of projects they have completed.
PART 2: MATERIALS
2.1 Modular Wall Units
A. Wall units shall be Allan Block Retaining Wall units as produced by a licensed manufacturer.
B. Wall units shall have minimum 28 day compressive strength of 3000 psi (20.7 MPa) in accordance with ASTM C1372.
The concrete units shall have adequate freeze-thaw protection in accordance with ASTM C1372 or an average absorption rate of 7.5 lb/ft³ (120 kg/m³) for northern climates and 10 lb/ft³ (160 kg/m³) for southern climates.
C. Exterior dimensions shall be uniform and consistent. Maximum dimensional deviations on the height of any two units
shall be 0.125 in. (3 mm).
D. Wall units shall provide a minimum of 110 lbs total weight per square foot of wall face area (555 kg/m²). Hollow cores
to be filled with wall rock and compacted by using plate compactor on top of wall units (see section 3.4). Unit weight
of wall rock in cores may be less than 100% depending on compacted base.
E. Exterior face shall be textured. Color as specified by owner.
F. Freeze Thaw Durability: Like all concrete products, dry-cast concrete SRW units are susceptible to freeze-thaw degradation with exposure to de-icing salts and cold temperature. This is a concern in northern tier states that use deicing
salts. Based on good performance experience by several agencies, ASTM C1372, Standard Specification for Segmental Retaining Wall Units should be used as a model, except that the compressive strength for the units should be increased to a minimum of 4,000 – 5,800 psi (28 - 40 MPa) unless local requirements dictate higher levels. Also,
maximum water absorption should be reduced and requirements for freeze-thaw testing increased.
a. Require a current passing ASTM C1262 or equivalent governing standard or public authority, test report from
material supplier in northern or cold weather climates.
b. See the Best Practices for SRW Design document for detailed information on freeze thaw durability testing criteria and regional temperature and exposure severity figures and tables to define the appropriate zone and
requirements for the project.
2.2 Wall Rock
A. Material must be well-graded compactible aggregate, 0.25 in. to 1.5 in., (6 mm-38 mm) with no more than 10% passing the #200 sieve. (ASTM D422)
B. Material behind and within the blocks may be the same material.
2.3 Infill Soil
A. Infill material shall be site excavated soils when approved by the on-site soils engineer unless otherwise specified in
the drawings. Unsuitable soils for backfill (heavy clays or organic soils) shall not be used in the reinforced soil mass.
Fine grained cohesive soils [<31° (Ref)] may be used in wall construction, but additional backfilling, compaction and
73
allanblock.com
water management efforts are required. Poorly graded sands, expansive clays and/or soils with a
plasticity index (PI) >20 or a liquid limit (LL) >40 should not be used in wall construction.
B. The infill soil used must meet or exceed the designed friction angle and description noted on the
design cross sections, and must be free of debris and consist of one of the following inorganic
allanblock.com
USCS soil types: GP, GW, SW, SP, GP-GM or SP-SM meeting the following gradation as
determined in accordance with ASTM D422.
Sieve Size
Percent Passing
C. Where additional fill is required, contractor shall submit sample and specifi1 in (25 mm)
100 - 75
cations to the wall design engineer or the on-site soils engineer for approval
No. 4
100 - 20
and the approving engineer must certify that the soils proposed for use has
properties meeting or exceeding original design standards.
No. 40
0 - 60
PART 3: WALL CONSTRUCTION
No. 200
0 - 35
3.1 Excavation
A. Contractor shall excavate to the lines and grades shown on the construction drawings. Contractor shall use caution
not to over-excavate beyond the lines shown, or to disturb the base elevations beyond those shown.
B. Contractor shall verify locations of existing structures and utilities prior to excavation. Contractor shall ensure all surrounding structures are protected from the effects of wall excavation.
3.2 Foundation Soil Preparation
A. Foundation soil shall be defined as any soils located beneath a wall.
B. Foundation soil shall be excavated as dimensioned on the plans and compacted to a minimum of 95% of Standard
Proctor (ASTM D698) prior to placement of the base material.
C. Foundation soil shall be examined by the on-site soils engineer to ensure that the actual foundation soil strength
meets or exceeds assumed design strength. Soil not meeting the required strength shall be removed and replaced
with acceptable material.
3.3 Base
A. The base material shall be the same as the Wall Rock material (Section 2.2) or a low permeable granular material.
B. Base material shall be placed as shown on the construction drawing. Top of base shall be located to allow bottom
wall units to be buried to proper depths as per wall heights and specifications.
C. Base material shall be installed on undisturbed native soils or suitable replacement fills compacted to a minimum of
95% Standard Proctor (ASTM D698).
D. Base shall be compacted at 95% Standard Proctor (ASTM D698) to provide a level hard surface on which to place
the first course of blocks. The base shall be constructed to ensure proper wall embedment and the final elevation
shown on the plans. Well-graded sand can be used to smooth the top 1/2 in. (13 mm) on the base material.
E. Base material shall be a 4 in. (100 mm) minimum depth for walls under 4 ft (1.2 m) and a 6 in. (150 mm) minimum
depth for walls over 4 ft (1.2 m).
allanblock.com
74
SPECIFICATIONS
3.5 Unit Installation
A. The first course of wall units shall be placed on the prepared base per the manufacturers installation recommendations. The units shall be checked for level and alignment as they are placed.
B. Ensure that units are in full contact with base. Proper care shall be taken to develop straight lines and smooth curves
on base course as per wall layout.
C. Fill all cores and cavities and a minimum of 12 in. (300 mm) behind the base course with wall rock. Use infill soils behind the wall rock and approved soils in front of the base course to firmly lock in place. Check again for level and
alignment. Use a plate compactor to consolidate the area behind the base course. All excess material shall be
swept from top of units.
D. Install next course of wall units on top of base course. Position blocks to be offset from seams of blocks below. Perfect "running bond" is not essential, but a 3 in. (75 mm) minimum offset is recommended. Check each block for proper alignment
and level. Fill all cavities in and around wall units and to a minimum of 12 in. (300 mm) depth behind block with wall rock.
Wall rock and infill soil placed in uniform lifts not exceeding 8 in. (200 mm). Compaction requirements for all soils in areas
in, around and behind the reinforced mass shall be compacted to 95% of maximum Standard Proctor dry density (ASTM
D698) with a moisture content control of +1% to -3% of optimum.
E. For taller wall applications, structural fill should be specified for a minimum bottom 1/3 to 1/2 of the reinforced fill. If
structural fill is not utilized in the reinforced mass, the depth of wall rock behind the block should be increased. See
the Best Practices for SRW Design document.
F. The consolidation zone shall be defined as 3 ft (0.9 m) behind the wall. Compaction within the consolidation zone shall be
accomplished by using a hand operated plate compactor and shall begin by running the plate compactor directly on
the block and then compacting in parallel paths from the wall face until the entire consolidation zone has been compacted. A minimum of two passes of the plate compactor are required with maximum lifts of 8 in. (200 mm). Expansive
or fine-grained soils may require additional compaction passes and/or specific compaction equipment such as a
sheepsfoot roller. Maximum lifts of 4 in. (100 mm) may be required to achieve adequate compaction within the consolidation zone. Employ methods using lightweight compaction equipment that will not disrupt the stability or batter
of the wall. Final compaction requirements in the consolidation zone shall be established by the engineer of record.
G. Install each subsequent course in like manner. Repeat procedure to the extent of wall height.
H. As with any construction work, some deviation from construction drawing alignments will occur. Variability in construction
of SRWs is approximately equal to that of cast-in-place concrete retaining walls. As opposed to cast-in-place concrete
walls, alignment of SRWs can be simply corrected or modified during construction. Based upon examination of numerous
completed SRWs, the following recommended minimum tolerances can be achieved with good construction techniques.
(see the pg 19 of AB Spec Book).
Vertical Control - ±1.25 in. (32 mm) max. over 10 ft (3 m) distance.
Horizontal Location Control - straight lines ±1.25 in. (32 mm) over a 10 ft (3 m) distance.
Rotation - from established plan wall batter : ±2.0°
3.6 Additional Construction Notes
A. When one wall branches into two terraced walls, it is important to note that the soil behind the lower wall is also the
foundation soil beneath the upper wall. This soil shall be compacted to a minimum of 95% of Standard Proctor (ASTM
D698) prior to placement of the base material. Achieving proper compaction in the soil beneath an upper terrace
prevents settlement and deformation of the upper wall. One way is to replace the soil with wall rock and compact in
8 in. (200 mm) lifts. When using on-site soils, compact in maximum lifts of 4 in. (100 mm) or as required to achieve
specified compaction.
B. Vertical filter fabric use is not suggested for use with cohesive soils. Clogging of such fabric creates unacceptable hydrostatic pressures in soil reinforced structures. When filtration is deemed necessary in cohesive soils, use a three dimensional filtration system of clean sand or filtration aggregate. Vertical filter fabric may be used to separate wall rock zone
from fine grained, sandy infill soils if the design engineer deems it necessary based on potential water migration from
above or below grade, through the reinforced zone into the wall rock on the project. Horizontal filter fabric should be
placed above the wall rock column to prevent soils from above migrating into the wall rock column.
C. Embankment protection fabric is used to stabilize rip rap and foundation soils in water applications and to separate
infill materials from the retained soils. This fabric should permit the passage of fines to preclude clogging of the material. Embankment protection fabric shall be a high strength polypropylene monofilament material designed to meet
or exceed typical Corps of Engineers plastic filter fabric specifications (CW-02215); stabilized against ultraviolet (UV)
degradation and typically exceeding the values on Table 1. (see the Water Management section of AB Spec Book).
D. Water management is of extreme concern during and after construction. Steps must be taken to ensure that drain
pipes are properly installed and vented to daylight or connected to an underground drainage system and a grading
plan has been developed that routes water away from the retaining wall location. Site water management is required both during construction of the wall and after completion of construction.
Consult the Allan Block Engineering Department for details 800-899-5309.
A specification subject to change without notice, this document was last updated on 4/21/2015.
75
allanblock.com
Geogrid Reinforcement Systems
SECTION 2
PART 1: GENERAL
1.1 Scope
Work includes furnishings and installing geogrid reinforcement, wall block, and backfill to the lines
and grades designated on the construction drawings and as specified herein.
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1.2 Applicable Section of Related Work
Section 1: Allan Block Modular Retaining Wall Systems. (See Section 1)
1.3 Reference Standards
See specific geogrid manufacturers reference standards.
Additional Standards:
A. ASTM D4595 - Tensile Properties of Geotextiles by the Wide-Width Strip Method
B. ASTM D5262 - Test Method for Evaluating the Unconfined Creep Behavior of Geogrids
C. ASTM D6638 Grid Connection Strength (SRW-U1)
D. ASTM D6916 SRW Block Shear Strength (SRW-U2)
E. GRI-GG4 - Grid Long Term Allowable Design Strength (LTADS)
F. ASTM D6706 - Test Method for Geogrid Pullout
1.4 Delivery, Storage, and Handling
A. Contractor shall check the geogrid upon delivery to assure that the proper material has been received.
B. Geogrid shall be stored above -10° F (-23° C).
C. Contractor shall prevent excessive mud, cementitious materials, or other foreign materials from coming in contact
with the geogrid material.
PART 2: MATERIALS
2.1 Definitions
A. Geogrid products shall be of high density polyethylene or polyester yarns encapsulated in a protective coating
specifically fabricated for use as a soil reinforcement material.
B. Concrete retaining wall units are as detailed on the drawings and shall be Allan Block Retaining Wall Units.
C. Drainage material is free draining granular material as defined in Section 1, 2.2 Wall Rock.
D. Infill soil is the soil used as fill for the reinforced soil mass.
E. Foundation soil is the in-situ soil.
2.2 Products
Geogrid shall be the type as shown on the drawings having the property requirements as described within the manufacturers specifications.
2.3 Acceptable Manufacturers
A manufacturer’s product shall be approved by the wall design engineer.
PART 3: WALL CONSTRUCTION
3.1 Foundation Soil Preparation
A. Foundation soil shall be excavated to the lines and grades as shown on the construction drawings, or as directed by
the on-site soils engineer.
B. Foundation soil shall be examined by the on-site soils engineer to assure that the actual foundation soil strength
meets or exceeds assumed design strength.
C. Over-excavated areas shall be filled with compacted backfill material approved by on-site soils engineer.
D. Contractor shall verify locations of existing structures and utilities prior to excavation. Contractor shall ensure all surrounding structures are protected from the effects of wall excavation.
3.2 Wall Construction
Wall construction shall be as specified under Section 1, Part 3, Wall Construction.
allanblock.com
SPECIFICATIONS
3.3 Geogrid Installation
A. Install Allan Block wall to designated height of first geogrid layer. Backfill and compact the wall rock and infill soil in
layers not to exceed 8 in. (200 mm) lifts behind wall to depth equal to designed grid length before grid is installed.
B. Cut geogrid to designed embedment length and place on top of Allan Block to back edge of lip, for AB and AB
Europa Collections, or the middle of the facing unit for the AB Fieldstone Collection. Extend away from wall
approximately 3% above horizontal on compacted backfill.
76
C. Lay geogrid at the proper elevation and orientations shown on the construction drawings or as directed by the wall
design engineer.
D. Correct orientation of the geogrid shall be verified by the contractor and on-site soils engineer. Strength direction is
typically perpendicular to wall face.
E. Follow manufacturers guidelines for overlap requirements. In curves and corners, layout shall be as specified in Design Details 9-12, in the AB Spec Book.
F. Place next course of Allan Block on top of grid and fill block cores with wall rock to lock in place. Remove slack and
folds in grid and stake to hold in place.
G. Adjacent sheets of geogrid shall be butted against each other at the wall face to achieve 100 percent coverage.
H. Geogrid lengths shall be continuous. Splicing parallel to the wall face is not allowed.
3.4 Fill Placement
A. Infill soil shall be placed in lifts and compacted as specified under Section 1, Part 3, Unit Installation.
B. Infill shall be placed, spread and compacted in such a manner that minimizes the development of slack or
movement of the geogrid.
C. Only hand-operated compaction equipment shall be allowed within 3 ft (0.9 m) behind the wall. This area shall be
defined as the consolidation zone. Compaction in this zone shall begin by running the plate compactor directly on
the block and then compacting in parallel paths from the wall face back, until the entire consolidation zone has
been compacted. A minimum of two passes of the plate compactor are required with maximum lifts of 8 in. (200
mm). Section 1, Part 3, Unit Installation.
D. When fill is placed and compaction cannot be defined in terms of Standard Proctor Density, then compaction shall
be performed using ordinary compaction process and compacted so that no deformation is observed from the
compaction equipment or to the satisfaction of the engineer of record or the site soils engineer.
E. Tracked construction equipment shall not be operated directly on the geogrid. A minimum fill thickness of 6 in. (150
mm) is required prior to operation of tracked vehicles over the geogrid. Turning of tracked vehicles should be kept to
a minimum to prevent tracks from displacing the fill and damaging the geogrid.
F. Rubber-tired equipment may pass over the geogrid reinforcement at slow speeds, less than 10 mph (16 Km/h). Sudden braking and sharp turning shall be avoided.
G. The infill soil shall be compacted to achieve 95% Standard Proctor (ASTM D698). Soil tests of the infill soil shall be submitted to the on-site soils engineer for review and approval prior to the placement of any material. The contractor is
responsible for achieving the specified compaction requirements. The on-site soils engineer may direct the contractor to remove, correct or amend any soil found not in compliance with these written specifications.
H. An independent testing firm should be hired by the owner to provide services.
I. Independent firm to keep inspection log and provide written reports at predetermined intervals to the owner.
J. Testing frequency should be set to establish a proper compaction protocol to consistently achieve the minimum
compaction requirements set by the design requirements. If full time inspection and testing at 8 inch (20 cm) lifts is
not provided, then the following testing frequency should be followed:
a. One test for every 8 inches (20 cm) of vertical fill placed and compacted, for every 25 lineal feet (7.6 m) of
retaining wall length, starting on the first course of block.
b. Vary compaction test locations to cover the entire area of reinforced zone; including the area compacted
by the hand-operated compaction equipment.
c. Once protocol is deemed acceptable, testing can be conducted randomly at locations and frequencies
determined by the on-site soils engineer.
K. Slopes above the wall must be compacted and checked in a similar manner.
77
allanblock.com
3.5 Special Considerations
A. Geogrid can be interrupted by periodic penetration of a column, pier or footing structure.
B. Allan Block walls will accept vertical and horizontal reinforcing with rebar and grout.
C. If site conditions will not allow geogrid embedment length, consider the following alternatives:
• Masonry Reinforced Walls
• Double Allan Block Wall
• Earth Anchors
• Rock Bolts
• No-Fines Concrete
• Soil Nailing
• Increased Wall Batter
See the AB Spec Book, Design Details.
D. Allan Block can be used in a wide variety of water applications.
See the AB Spec Book, Section 3, Part 1.8.
allanblock.com
Consult the Allan Block Engineering Department for details 800-899-5309.
A specification subject to change without notice, this document was last updated on 10/15/2014.
TECHNICAL SUPPORT
For engineering and technical assistance on projects that fall beyond the scope of these guidelines,
contact ALLAN BLOCK CORPORATION at 800-899-5309.
Reference Guide
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16
18)
19)
20)
Allan Block Engineering Manual, November 2014
Allan Block Spec Book, Juy 2015
Allan Block Seismic Testing Executive Summary, November 2007
Best Practices for SRW Design, December 2014
Allan Block Evaluation Report, Published August 2011
Load Bearing Concrete Masonry Units
Sampling and Testing, Concrete Masonry Units
Hollow and Solid Load Bearing Concrete Masonry Units
Standard Specification for Segmental Retaining Wall Units
Evaluating Freeze Thaw Durability
Building Code Requirements for Reinforced Concrete
Standard Test Method for Determining the Shear Strength between Segmental Concrete Units
Standard Test Method for Determining Connection Strength between Geosynthetic
Reinforcement and Segmental Concrete Units
FHWA-NHI-02-011
Mechanically Stabilized Earth Walls and Reinforced Soil Slopes
Jones, Colin JFP, Earth Reinforcement and Soil Structures, Butterworths, London, England (1985)
Mitchell, J K, et. al. Reinforcement of Earth Slopes and Embankments, NCHRP Report 290, Transportation Research Board,
Washington, DC (1987)
Task Force 27, In-Situ Soil Improvement Techniques, “Design Guidelines for Use of Extensible Reinforcements for Mechanically
Stabilized Earth Walls in Permanent Applications,” Joint Committee of AASHTO-AGC-ARTBA, AASHTO, Washington, DC (1990)
Terzaghi, K, and Peck, R B, Soil Mechanics in Engineering Practice, John Wiley and Sons, Inc., New York, NY (1967)
GRI Standard Practice, GG4 : Determination of Long-Term Design Strength of Geogrids, Geosynthetic Research Institute,
Drexel University, Philadelphia, PA (1991)
Hoe I. Ling, et. al. Large-Scale Shaking Table Tests on Modular-Block Reinforced Soil Retaining Walls, Tsukuba, Japan (2005)
allanblock.com
78
SPECIFICATIONS
17)
R0904-1114
R0901-0812
R0903-1107
R0615-1214
IAPMO #ER-0198
ASTM C90
ASTM C140
UBC 21
ASTM C1372
ASTM C1262
ACI 318
ASTM D6916
ASTM D6638
79
allanblock.com
Engineered for Performance
Allan Block provides the engineering flexibility to meet the
most challenging design requirements including water and
shoreline sites. Allan Block is fully engineered and tested and
is the only retaining wall system to pass full seismic testing.
When proven performance is important, choose Allan Block.
allanblock.com
80
Site Solutions
Allan Block’s extensive engineering provides the
capability to meet a broad variety of applications.
From sound barriers to industrial applications the
Allan Block product can meet your needs. It’s cost
effective, long term performance makes it the
product of choice for DOT projects across the
country. It can be designed to accommodate
the toughest federal, state and provincial
specifications including applicable AASHTO
and Task Force 27 requirements.
Allan Block has conducted the only full-scale seismic
research for segmental retaining walls. The flexible
nature and performance of the AB System astounded
the experts. You can feel secure in knowing your
Allan Block solution can withstand the test of time.
81
allanblock.com
AB Fence® System
To find the most up-to-date
information as well as the
other Allan Block products
available, visit allanblock.com.
AB Courtyard Collection®
allanblock.com
82
Color: Kasota Gold
Facing Series: Colonial
Color: Rustic Creek
Color: Sandstone
83
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Looking Towards the Future
The next generation of Allan Block products is
here; AB Fieldstone - Green, Natural and Friendly.
The patented two-piece system enables us to
push the envelope in aesthetics, sustainability,
and product opportunity.
So look to the future with us as Allan Block
continues to innovate. Expect to see more of
AB Fieldstone and all it has to offer as the next
great wall solution, from the company you have
come to trust – Allan Block.
About Us
With the same plan, design and build process as the
other Allan Block retaining wall systems, you can
now have AB Fieldstone. The most innovative Green,
Natural and Friendly product on the market.
Allan Block is a leading provider of
patented retaining wall systems for
large-scale commercial, industrial,
roadway and residential projects.
AB Fieldstone Typical Reinforced Wall Cross Section
For over twenty years, Allan Block
has been helping landscape and
construction professionals build better
walls. With hundreds of millions of
square feet of Allan Block in the
ground, we can deliver the quality
and performance you need. Our wide
range of products allows you to be
creative, efficient, and confident on
every job.
Thank you for using Allan Block.
1
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allanblock.com
84
The information and product applications illustrated in this manual have been carefully compiled by
the Allan Block Corporation and, to the best of our knowledge, accurately represent Allan Block
product use. Final determination of the suitability of any information or material for the use
contemplated and its manner of use is the sole responsibility of the user. Structural design analysis shall
be performed by a qualified engineer.
allanblock.com
Commercial Installation Manual for
Allan Block Retaining Walls
®
allanblock.com
Printed on
Paper with 10%
Recycled Fiber
©2014, 2011, 2008 Allan Block Corporation, Bloomington, MN Phone 952-835-5309, Fax 952-835-0013, US Pat. #5,484,236, #6,792,731, #6,322,742 & #6,854,236 Canadian Pat.
#2,012,286 & #2,133,675 Australian Pat. #682,394 & #133,306 Europe Pat. #649,714 & #99,308,421.9 Germany Pat. #69,423,563.6 Japan Pat. #3,142,107
Mexico Pat. #189,846 Taiwan Pat. #NI-72269 AB Fieldstone Pat. #7,775,747 & D624,204S Int’l And Other Patents Pending DOC. #R0514-1214
allanblock.com

Retaining Wall Installation Manual for Commercial

Transcription

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